MIRU evidence library

Read the receipts.

See what was studied, how strong it is and where the evidence stops. Every entry below has at least one source you can open.

Check the formula

30 ingredients · 62 linked sources

Find a receipt

Evidence level

30 of 30 records

StrongNiacinamide · applied to skin

Full record

Well studied in relation to a calmer, more even-looking complexion and a supported skin barrier.

Studied as Niacinamide: 5% niacinamide.

Sources · 2

Double-blind split-face, 5% niacinamide, 12 weeks: significant reductions in fine lines, hyperpigmented spots, red blotchiness and sallowness; improved elasticity.
fine lines, hyperpigmented spots, red blotchiness, sallowness, elasticity · 5% niacinamide
Dermatologic Surgery, 2005
Confirmed reductions in yellowing, wrinkling, red blotchiness and hyperpigmented spots.
yellowing, wrinkling, red blotchiness, hyperpigmented spots
Int J Cosmetic Science, 2004

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongSunscreen / SPF · applied to skin

Full record

One of the best-studied things you can do in relation to keeping skin looking younger over time. The prevention step that’s hard to beat.

Studied as Sunscreen / SPF: broad-spectrum SPF 15+, daily.

Sources · 1

RCT, 4.5 years: daily-sunscreen group showed 24% less skin aging than discretionary use (OR 0.76, 95% CI 0.59–0.98).
skin aging · broad-spectrum SPF 15+, daily
Annals of Internal Medicine, 2013

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateCeramides · applied to skin

Full record

Studied in relation to a stronger, better-hydrated skin barrier. Part of the skin’s own lipid structure.

Sources · 2

Systematic review and meta-analysis in atopic dermatitis, five studies: ceramide-containing moisturisers improved SCORAD against other moisturisers (mean difference -0.98, P=0.003). Transepidermal water loss was NOT significantly different (-3.56, P=0.17, high heterogeneity).
atopic-dermatitis severity, transepidermal water loss
Indian J Dermatol, 2023
Randomised, investigator-blinded, intra-individual comparison in patients with controlled atopic dermatitis: a ceramide-precursor moisturiser on one lower leg against the untreated other leg for 4 weeks gave greater reduction in transepidermal water loss and clinical dryness and higher hydration (all P<.01).
transepidermal water loss, dryness, hydration
J Dermatolog Treat, 2013

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedRetinol (over the counter) · applied to skin

Full record

Studied in relation to fine lines and surface texture, with results that vary a lot between trials.

Studied as Retinol (over the counter): 0.4% retinol lotion.

Retinol is not the same molecule as prescription tretinoin and the evidence is not the same either. Trials are small, formulations differ, and an over the counter product is not required to state how much retinol it contains.

Sources · 2

Systematic review of nine randomised trials: four found no significant difference between retinol and vehicle. The five that did gave weak evidence for a mild effect on fine wrinkle lines only, with major methodological flaws.
fine facial wrinkles
J Clin Aesthet Dermatol, 2021
Vehicle-controlled trial of 0.4% retinol in ARM skin, 24 weeks, in 36 residents of two senior citizen facilities, mean age 87: fine wrinkle scores improved against vehicle (-1.64 vs -0.08, P<.001), with higher glycosaminoglycan and procollagen I expression.
fine wrinkles, skin matrix synthesis · 0.4% retinol lotion
Arch Dermatol, 2007

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongAzelaic acid · applied to skin

Full record

Well studied in relation to calmer, clearer, more even-looking skin. And tends to be gentle.

Studied as Azelaic acid: 15–20% azelaic acid.

Sources · 1

15–20% azelaic acid gave meaningful improvement across acne, rosacea and melasma; 20% comparable to hydroquinone for melasma.
acne, rosacea, melasma · 15–20% azelaic acid
J Cosmet Dermatol (43-trial review), 2023

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedSalicylic acid (BHA) · applied to skin

Full record

Studied in relation to clearer, less congested skin. Most of the record is in-clinic peels rather than the products on a shelf.

Studied as Salicylic acid (BHA): leave-on topical, in-clinic chemical peel.

The everyday leave-on comparison rests on low-quality evidence from a small trial. Salicylic acid evidence is not equivalent to tretinoin evidence, and timing depends on the formulation you are holding.

Sources · 3

Cochrane review: for people rating their own acne there may be little or no difference between salicylic acid and tretinoin, on low-quality evidence from 46 participants. Risk of bias and imprecision limit confidence.
acne · leave-on topical
Cochrane Database Syst Rev, 2020
Review of salicylic acid AS A PEELING AGENT: its comedolytic action makes it a useful peel for acne across skin types. It does not study leave-on products.
acne, comedones · in-clinic chemical peel
Clin Cosmet Investig Dermatol, 2015
Peel RCT: reduced non-inflammatory lesions (~48.5% from baseline by Day 98).
non-inflammatory acne lesions · in-clinic chemical peel
J Cosmet Dermatol, 2011

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongAdapalene · applied to skin

Full record

Well studied in relation to clearer skin, most often alongside benzoyl peroxide.

Studied as Adapalene: adapalene with benzoyl peroxide.

Sources · 1

Systematic review of 8 randomised controlled trials, 4,596 participants, compared against vehicle or single-agent treatment: acne lesion reduction ranged from 27.5% to 70.2%, and the review concludes the combination is safe and effective. Adverse effects ranged from 2.7% to 57.9% and were mild.
acne · adapalene with benzoyl peroxide
Cureus, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateAHAs (glycolic/lactic) · applied to skin

Full record

Studied in relation to smoother, more refined-looking skin over time.

Studied as AHAs (glycolic/lactic): 8% glycolic cream, 8% lactic cream.

Sources · 2

Vehicle-controlled: 8% glycolic and 8% lactic creams improved photodamage in 76%/71% of facial sides vs 40% vehicle.
photodamage · 8% glycolic cream, 8% lactic cream
Archives of Dermatology, 1996
AHAs produced ~25% increase in skin thickness with epidermal and dermal remodelling.
skin thickness, dermal remodelling
J Am Acad Dermatol, 1996

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateBakuchiol · applied to skin

Full record

In one 12-week trial of 44 people, 0.5% bakuchiol twice daily and 0.5% retinol once daily both improved wrinkles and pigmentation, with no statistically significant difference between groups; retinol caused more scaling and stinging.

Studied as Bakuchiol: 0.5% bakuchiol cream twice daily, 0.5% retinol cream once daily, bakuchiol alone or in combination formulas, genistein, bakuchiol, vitamins and ceramides combination product.

This was one small head-to-head study with no plain-cream arm and different dosing schedules, not a non-inferiority or equivalence trial. Most other human studies in a systematic review were uncontrolled or tested combination formulas, and none of these sources establishes pregnancy safety.

Sources · 3

Randomized double-blind head-to-head study in 44 people over 12 weeks: both groups improved from baseline on wrinkle surface area and hyperpigmentation, with no statistically significant difference between groups; retinol users reported more scaling and stinging. There was no vehicle arm and the schedules differed.
wrinkle surface area, hyperpigmentation, scaling, stinging · 0.5% bakuchiol cream twice daily, 0.5% retinol cream once daily
Br J Dermatol, 2019
Systematic review of 29 included reports found 16 preclinical studies and seven clinical studies; the evidence base was predominantly preclinical and the authors called for additional rigorous controlled human trials.
photoageing, acne, post-inflammatory hyperpigmentation, adverse events · bakuchiol alone or in combination formulas
J Cosmet Dermatol, 2022
Randomized double-blind placebo-controlled trial in 80 men over 12 weeks: the combination modestly improved lightness, colour evenness, spots and some roughness measures, but not melanin, erythema, acne or elasticity. Bakuchiol was not tested alone.
skin lightness, colour evenness, spots, roughness, melanin, erythema, acne, elasticity · genistein, bakuchiol, vitamins and ceramides combination product
Skin Res Technol, 2026

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongBenzoyl peroxide · applied to skin

Full record

Well studied in relation to clearer skin. A long-standing, dermatologist-backed option for breakouts.

Studied as Benzoyl peroxide: adapalene with benzoyl peroxide.

Sources · 1

Systematic review of 8 randomised controlled trials, 4,596 patients, compared against vehicle or single-agent treatment: acne lesion reduction ranged from 27.5% to 70.2%, and the review concludes the combination is safe and effective. It also states that combining a retinoid with benzoyl peroxide does not contribute to antibiotic resistance.
acne · adapalene with benzoyl peroxide
Cureus, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedCentella asiatica (cica) · applied to skin

Full record

Encouraging early evidence in relation to calmer, more comfortable skin. A long-used soothing botanical.

Studied as Centella asiatica (cica): standardised Centella extract, madecassoside.

Sources · 2

Review of topical Centella asiatica. The one controlled human result it reports for erythema is a split-face, double-blind, placebo-controlled trial of 0.05% standardised ECa 233 gel after laser resurfacing for acne scars, in which erythema subsided by day 7 against day 28 on the placebo side (Damkerngsuntorn et al. 2020). The review also describes the actives enhancing collagen synthesis and modulating inflammation.
post-laser erythema, collagen synthesis · standardised Centella extract
Pharmaceutics, 2024
Madecassoside facilitated wound healing via antioxidative activity and collagen synthesis (pre-clinical).
wound healing · madecassoside
J Ethnopharmacol, 2008

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongColloidal oatmeal · applied to skin

Full record

A complete 1% colloidal oatmeal cream was non-inferior to a named prescription barrier cream over three weeks in 90 children with mild-to-moderate atopic dermatitis.

Studied as Colloidal oatmeal: complete 1% colloidal oatmeal cream, ceramide-based prescription barrier cream, fluocinolone 0.025% for two weeks followed by 1% colloidal oatmeal cream, fluocinolone 0.025% for two weeks followed by base cream, colloidal oatmeal at 0.007% minimum, colloidal oatmeal at 0.003% minimum with mineral oil.

The non-inferiority result applies to the tested complete 1% cream and its prescription barrier-cream comparator, not colloidal oatmeal in isolation. The hand-eczema study used fluocinolone for the first two weeks before the oatmeal-versus-base phase. FDA monograph concentrations are regulatory facts, not clinical efficacy thresholds.

Sources · 3

Double-blind randomized active-controlled study in 90 children over three weeks: the complete 1% colloidal oatmeal cream was non-inferior to the prescription barrier cream for EASI, using a prespecified 1.5-point non-inferiority margin.
eczema area and severity index, itch, global atopic-dermatitis assessment · complete 1% colloidal oatmeal cream, ceramide-based prescription barrier cream
J Dermatolog Treat, 2017
Double-blind randomized study with 50 completers: both groups improved during the two-week fluocinolone lead-in; during the following four weeks, the oatmeal arm held improvement while symptoms in the base-cream arm returned toward baseline.
hand eczema severity, itch, dermatology life quality index · fluocinolone 0.025% for two weeks followed by 1% colloidal oatmeal cream, fluocinolone 0.025% for two weeks followed by base cream
Clin Cosmet Investig Dermatol, 2020
The US OTC skin-protectant monograph names colloidal oatmeal itself as an active ingredient at a minimum 0.007%, or 0.003% when combined with mineral oil under the specified monograph condition.
skin-protectant regulatory status · colloidal oatmeal at 0.007% minimum, colloidal oatmeal at 0.003% minimum with mineral oil
FDA OTC Monograph M016, 2021

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateEctoin · applied to skin

Full record

Short clinical studies of ectoin-containing creams reported improved eczema severity scores; the vehicle-controlled trial used ectoin together with hyaluronic acid.

Studied as Ectoin: ectoin-containing cream EHK02-01, nonsteroidal anti-inflammatory reference cream, 1% ectoine with 0.1% hyaluronic acid cream, vehicle cream, 5.5–7% ectoin-containing topical formulations.

Studies were small and short. One used an active comparator rather than a plain vehicle, one tested ectoin with hyaluronic acid, and the systematic review had an industry-employed author. They do not prove every ectoin product works the same way.

Sources · 3

Randomized intra-individual double-blind multicentre trial in 65 adults with mild-to-moderate atopic dermatitis: after 28 days, the ectoin-containing cream performed equivalently to an active nonsteroidal reference cream. There was no plain-vehicle arm.
local eczema severity, investigator assessment, itch · ectoin-containing cream EHK02-01, nonsteroidal anti-inflammatory reference cream
Skin Pharmacol Physiol, 2014
Randomized observer-blind vehicle-controlled four-week trial in children aged 2–18: 70 were randomized and 57 analysed; the combination cream improved objective SCORAD versus vehicle (P < .001), but ectoin was not tested alone. Mild cutaneous adverse events occurred in 23.5% versus 5.7%.
objective SCORAD, investigator assessment, itch, cutaneous adverse events · 1% ectoine with 0.1% hyaluronic acid cream, vehicle cream
Pediatr Dermatol, 2023
Systematic review of six clinical studies (five in atopic dermatitis, one in retinoid dermatitis): outcomes generally favoured ectoin-containing formulations, but many studies were open-label, adjunctive or low-certainty and one author was employed by Bitop AG.
skin dryness, itch, dermatitis severity · 5.5–7% ectoin-containing topical formulations
Dermatol Ther (Heidelb), 2022

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedFerulic Acid · applied to skin

Full record

Small human studies found less UV-related redness and damage markers after four days with complete antioxidant combinations containing ferulic acid.

Studied as Ferulic Acid: 15% L-ascorbic acid with 1% alpha-tocopherol, the same formula with 0.5% ferulic acid, 15% L-ascorbic acid with 1% alpha-tocopherol and 0.5% ferulic acid, vehicle, vitamin C with ferulic acid and phloretin.

Ferulic acid was never isolated from the vitamin C, vitamin E or phloretin formulas. One human trial had 10 participants, another reported only a small sample, and the widely cited eightfold result came from pig, not human, skin. These formulas may complement sunscreen; they do not replace it.

Sources · 3

Porcine-skin study: adding 0.5% ferulic acid stabilized the vitamin C and E formula and increased its reported photoprotection from about fourfold to about eightfold. This was pig, not human, skin and did not test ferulic acid alone.
formula stability, erythema, sunburn cells, thymine dimers · 15% L-ascorbic acid with 1% alpha-tocopherol, the same formula with 0.5% ferulic acid
J Invest Dermatol, 2005
Small human in-vivo study over four days: the complete vitamin C, vitamin E and ferulic acid formula reduced several solar-simulated-radiation damage markers versus vehicle. The abstract did not report the sample size, and ferulic acid was not isolated.
erythema, sunburn cells, thymine dimers, p53, inflammatory cytokines · 15% L-ascorbic acid with 1% alpha-tocopherol and 0.5% ferulic acid, vehicle
J Am Acad Dermatol, 2008
Randomized four-day human study in 10 participants: the complete vitamin C, ferulic acid and phloretin formula reduced several UV-related damage markers versus vehicle. Ferulic acid was not tested alone, and one author was affiliated with L’Oreal USA.
erythema, sunburn cells, thymine dimers, MMP-9, p53, Langerhans cells · vitamin C with ferulic acid and phloretin, vehicle
J Cosmet Dermatol, 2009

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongGlycerin · applied to skin

Full record

Human studies of complete creams found that 20% glycerin increased measured skin hydration; effects on other endpoints depended on the formulation.

Studied as Glycerin: 20% glycerin cream, vehicle cream, cream base without glycerin, 4% urea plus 4% sodium chloride cream, glycerol plus petrolatum emollient, vehicle, vehicle plus glycerol, vehicle plus petrolatum.

These studies tested complete creams, not glycerin in isolation. One short vehicle-controlled study found no added improvement in transepidermal water loss or surfactant response, and a separate comparator trial found equal improvement in dryness rather than superiority.

Sources · 3

Bilateral randomized double-blind study in 17 healthy volunteers over 10 days: the 20% glycerin cream increased measured skin hydration versus vehicle, but did not improve transepidermal water loss or the response to sodium lauryl sulphate.
skin hydration, transepidermal water loss, sodium lauryl sulphate irritation response · 20% glycerin cream, vehicle cream
Int J Cosmet Sci, 2001
Randomized double-blind study in 197 people with atopic dermatitis over 30 days: dryness improved equally with the glycerin and urea/saline creams; moderate or severe smarting was reported by 10% with glycerin versus 24% with urea/saline.
dryness, smarting · 20% glycerin cream, cream base without glycerin, 4% urea plus 4% sodium chloride cream
Acta Derm Venereol, 2002
Randomized double-blind four-arm crossover study in 51 people measured over 12 hours: the complete emollient outperformed vehicle; the glycerol component contributed to hydration while petrolatum contributed to the transepidermal-water-loss effect.
transepidermal water loss, corneometry · glycerol plus petrolatum emollient, vehicle, vehicle plus glycerol, vehicle plus petrolatum
J Cosmet Dermatol, 2020

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateHyaluronic acid (topical) · applied to skin

Full record

One 60-day, 0.1% periocular study reported hydration and elasticity improvements across the tested molecular weights; wrinkle-depth improvement was limited to the 50 and 130 kDa arms.

Studied as Hyaluronic acid (topical): 0.1% hyaluronan at 50, 130, 300, 800 or 2,000 kDa.

Sources · 1

Split-area, vehicle-controlled study in 76 women over 60 days: all five 0.1% periocular hyaluronan preparations improved measured hydration and elasticity versus vehicle; wrinkle-depth improvement was reported only for the 50 and 130 kDa arms. The paper’s penetration explanation is speculative, not a demonstrated outcome.
periocular hydration, periocular elasticity, periocular wrinkle depth · 0.1% hyaluronan at 50, 130, 300, 800 or 2,000 kDa
J Drugs Dermatol, 2011

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedKojic Acid · applied to skin

Full record

One 12-week study compared 1% kojic acid alone with three combinations and found the hydroquinone combination performed best; a newer pilot found an alpha-arbutin and kojic-acid cream similar to triple therapy on two pigmentation scores.

Studied as Kojic Acid: 1% kojic acid cream, 1% kojic acid + 2% hydroquinone cream, 1% kojic acid + 0.1% betamethasone valerate cream, 1% kojic acid + 2% hydroquinone + 0.1% betamethasone valerate cream, 5% alpha-arbutin + 2% kojic acid cream, triple combination cream.

Neither study proves kojic acid alone against a plain cream: the first was single-blind, single-centre and had no vehicle arm; the newer study was a 30-person combination pilot and did not isolate kojic acid.

Sources · 2

Randomized single-blind, single-centre study in 80 people over 12 weeks: the kojic-acid and hydroquinone combination had the greatest decrease in melasma severity, followed by the triple combination and kojic acid alone; every arm contained kojic acid and there was no vehicle control.
melasma area and severity index · 1% kojic acid cream, 1% kojic acid + 2% hydroquinone cream, 1% kojic acid + 0.1% betamethasone valerate cream, 1% kojic acid + 2% hydroquinone + 0.1% betamethasone valerate cream
Indian J Dermatol, 2013
Split-face randomized evaluator-blinded pilot in 30 people over 12 weeks plus four weeks follow-up: melanin-index and modified-MASI changes did not differ between the alpha-arbutin/kojic-acid cream and triple therapy; physician assessment improved only on the triple-therapy side, while recurrence severity, erythema and stinging were higher there. Kojic acid was not tested alone.
melanin index, modified melasma area severity index, physician global assessment, recurrence, adverse effects · 5% alpha-arbutin + 2% kojic acid cream, triple combination cream
J Cosmet Dermatol, 2025

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedKTTKS (Lys-Thr-Thr-Lys-Ser) · applied to skin

Full record

The held evidence is an ex-vivo stability and distribution study of the exact KTTKS sequence in hairless-mouse skin.

Studied as KTTKS (Lys-Thr-Thr-Lys-Ser): KTTKS, palmitoyl-KTTKS.

Unmodified KTTKS was absent from every measured skin layer and from receptor solution. The Palmitoyl Pentapeptide-4 clinical literature does not transfer to KTTKS.

Sources · 1

Ex-vivo full-thickness hairless-mouse skin: neither KTTKS nor pal-KTTKS reached receptor solution. Unmodified KTTKS was absent from the measured skin layers, while pal-KTTKS was detected in stratum corneum and epidermis with a small dermal amount. This does not establish human permeation or a clinical effect for KTTKS.
ex-vivo hairless-mouse skin distribution, dermal stability · KTTKS, palmitoyl-KTTKS
Biomol Ther (Seoul), 2014

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedLiquiritin · applied to skin

Full record

One small four-week split-face controlled trial in 20 women with epidermal melasma reported improvement with 1% liquiritin cream versus vehicle.

Studied as Liquiritin: 1% liquiritin cream.

This is one small, short study. The PubMed record does not state randomization or blinding, and the study included no hydroquinone or kojic-acid comparator, so it cannot establish comparative tolerability.

Sources · 1

Twenty women with bilateral epidermal melasma used liquiritin cream on one side of the face and vehicle on the other twice daily for four weeks. The report describes improvement with 1% liquiritin, but the PubMed abstract does not state randomization or blinding and names no active comparator.
epidermal melasma pigmentation · 1% liquiritin cream
Int J Dermatol, 2000

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedPalmitoyl Pentapeptide-4 (pal-KTTKS) · applied to skin

Full record

The held evidence is specific to Palmitoyl Pentapeptide-4 (pal-KTTKS), not to peptides as a class.

Studied as Palmitoyl Pentapeptide-4 (pal-KTTKS): KTTKS, palmitoyl-KTTKS, Palmitoyl Pentapeptide-4.

The permeation study used ex-vivo hairless-mouse skin and detected neither KTTKS nor pal-KTTKS in receptor solution. The clinical literature named by the review concerns Palmitoyl Pentapeptide-4 specifically.

Sources · 2

Ex-vivo full-thickness hairless-mouse skin: neither KTTKS nor pal-KTTKS reached receptor solution. KTTKS was absent from the measured skin layers; pal-KTTKS was detected in stratum corneum and epidermis, with a small dermal amount. This is animal-skin distribution evidence, not human permeation.
ex-vivo hairless-mouse skin distribution, dermal stability · KTTKS, palmitoyl-KTTKS
Biomol Ther (Seoul), 2014
Narrative review names Palmitoyl Pentapeptide-4 as the well-researched molecule and cites Robinson et al. 2005 for a controlled study in photoaged human facial skin. It does not establish a result for peptides as a class.
narrative review of topical peptide treatments · Palmitoyl Pentapeptide-4
Cosmetics, 2017

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModeratePanthenol (pro-vitamin B5) · applied to skin

Full record

Studied in relation to soothed, better-hydrated skin. A gentle barrier supporter.

Studied as Panthenol (pro-vitamin B5): panthenol emollient.

Sources · 2

Topical dexpanthenol acts as a humectant and barrier enhancer, increasing stratum-corneum hydration.
stratum-corneum hydration, barrier function
Am J Clin Dermatol, 2002
Two RCTs: panthenol emollient improved hydration and barrier-restoration vs control.
hydration, barrier restoration · panthenol emollient
J Dermatolog Treat, 2017

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateRetinaldehyde · applied to skin

Full record

Two small controlled studies found retinaldehyde improved fine lines or skin elasticity versus a plain cream, with less irritation than retinoic acid.

Studied as Retinaldehyde: 0.05% retinaldehyde cream, 0.05% retinoic acid cream, vehicle cream.

Both controlled studies are more than 25 years old; samples were small and several secondary measurements did not improve.

Sources · 2

Randomized vehicle-controlled trial in 125 people over 44 weeks: retinaldehyde and retinoic acid improved wrinkle and roughness measures while vehicle did not; retinoic acid was more irritating than retinaldehyde.
wrinkle profilometry, skin roughness, tolerability · 0.05% retinaldehyde cream, 0.05% retinoic acid cream, vehicle cream
J Am Acad Dermatol, 1998
One-year controlled study in 40 people: retinaldehyde increased epidermal thickness and elasticity versus control, while dermal thickness and stiffness did not significantly change.
epidermal thickness, skin elasticity, dermal thickness, skin stiffness · 0.05% retinaldehyde cream
Dermatology, 1999

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongRetinoids (class) · applied to skin

Full record

Topical retinoids as a class are among the most studied ingredients for skin texture over time.

Studied as Retinoids (class): adapalene with benzoyl peroxide.

Sources · 1

The review names retinoids, antibiotics and benzoyl peroxide as the main treatment options for acne, and states that a retinoid with benzoyl peroxide is safe and effective without contributing to antibiotic resistance. (Its own trial data is eight adapalene/benzoyl-peroxide trials and is adapalene/BPO specific.)
acne · adapalene with benzoyl peroxide
Cureus, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedSnail Secretion Filtrate · applied to skin

Full record

One small placebo-controlled trial found fewer inflammatory lesions with a three-ingredient serum containing snail secretion filtrate.

Studied as Snail Secretion Filtrate: snail secretion filtrate, calendula and licorice serum, placebo serum, snail mucin and snail extract preparations.

The serum also contained calendula and licorice, so the effect cannot be attributed to snail secretion filtrate alone. Non-inflammatory lesions and measured skin biophysics did not differ; a 2024 review found most wider claims rest on preclinical or small clinical studies.

Sources · 2

Twelve-week randomized double-blind placebo-controlled trial in 66 people with mild-to-moderate mask-related acne: the three-ingredient serum reduced inflammatory lesions more than placebo, while non-inflammatory lesions and measured skin biophysics did not significantly differ. Snail secretion filtrate was not tested alone.
inflammatory acne lesions, non-inflammatory acne lesions, sebum, corneometry, transepidermal water loss, erythema · snail secretion filtrate, calendula and licorice serum, placebo serum
J Cosmet Dermatol, 2022
Literature review of medical and cosmetic uses: most studies were preclinical or small clinical studies, and larger clinical trials are needed to support claimed benefits and clarify safety and ethical-extraction questions.
clinical evidence limitations, allergy investigation, ethical extraction · snail mucin and snail extract preparations
J Cosmet Dermatol, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedTranexamic Acid · applied to skin

Full record

One small vehicle-controlled trial found 5% topical tranexamic acid no better than its vehicle after 12 weeks and reported more redness.

Studied as Tranexamic Acid: 5% topical tranexamic acid gel, vehicle gel, oral tranexamic acid, injected tranexamic acid, topical tranexamic acid, 2% tranexamic acid with 2% niacinamide niosomal cream, 5% tranexamic acid with 4% niacinamide conventional cream, 4% hydroquinone cream.

The dedicated topical trial enrolled 23 women and 21 completed. A 22-trial review mixed topical, injected, and oral routes and had high heterogeneity. A separate 99-person study compared tranexamic-acid and niacinamide combination creams with 4% hydroquinone, so it did not isolate tranexamic acid or prove the formulas equivalent.

Sources · 3

Double-blind 12-week split-face trial: 23 women enrolled and 21 completed. The 5% tranexamic acid side was neither superior nor different from vehicle for pigmentation, while erythema was significantly higher on the tranexamic-acid side.
melanin index, melasma severity, erythema · 5% topical tranexamic acid gel, vehicle gel
J Cosmet Laser Ther, 2012
Systematic review and meta-analysis of 22 randomised trials with 1,280 patients. Oral treatment showed the largest pooled MASI decrease, followed by injections and topical applications; studies had high heterogeneity, especially among combination treatments.
melasma severity, adverse effects · oral tranexamic acid, injected tranexamic acid, topical tranexamic acid
J Dermatolog Treat, 2024
Randomised double-blind 99-person comparison of two tranexamic-acid and niacinamide combination creams with 4% hydroquinone. Because neither test cream isolated tranexamic acid and the comparator was active, the trial does not establish tranexamic acid alone or prove equivalence.
melanin index, melasma severity, quality of life, adverse reactions, relapse · 2% tranexamic acid with 2% niacinamide niosomal cream, 5% tranexamic acid with 4% niacinamide conventional cream, 4% hydroquinone cream
Sci Rep, 2025

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongTretinoin · applied to skin

Full record

Well studied in relation to fine lines, mottled pigmentation and surface texture over months of use.

Tretinoin is a prescription medicine in most countries, and irritation early on is the usual reason people stop. Someone who can see your skin should hold the plan.

Sources · 3

Seven randomised controlled trials: all reported topical tretinoin improving the clinical appearance of photoaging (wrinkling, mottled hyperpigmentation, sallowness and lentigines) as early as 1 month, and still present after 24 months.
photoaging, wrinkling, mottled hyperpigmentation, sallowness, lentigines
Int J Womens Dermatol, 2022
Meta-analysis of eight trials and 1,361 patients: topical tretinoin significantly improved both fine and coarse facial wrinkles from photodamage.
fine wrinkles, coarse wrinkles
Dermatol Pract Concept, 2025
AAD acne guideline: strong recommendations for topical retinoids alongside benzoyl peroxide, topical antibiotics and oral doxycycline. Acne, not photoaging.
acne vulgaris
J Am Acad Dermatol, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongTrifarotene (prescription topical) · applied to skin

Full record

Two 12-week randomized, double-blind, vehicle-controlled phase 3 trials found greater facial and truncal acne improvement with trifarotene 0.005% cream than vehicle.

Studied as Trifarotene (prescription topical): 0.005% trifarotene cream.

Trifarotene is a prescription retinoid. Local irritation and ultraviolet-exposure precautions apply. The trial author list included employees of Galderma R&D, the manufacturer's research organization; neither held source compares trifarotene with another retinoid or establishes adjunctive-treatment benefit.

Sources · 2

Two separate 12-week randomized, double-blind, vehicle-controlled phase 3 trials in patients aged 9 years or older found trifarotene 0.005% cream superior to vehicle on investigator success and inflammatory and non-inflammatory lesion counts on the face and trunk. The author list included employees of Galderma R&D.
facial acne vulgaris, truncal acne vulgaris · 0.005% trifarotene cream
J Am Acad Dermatol, 2019
The current U.S. prescribing information, revised October 2023, indicates topical 0.005% trifarotene cream for acne vulgaris on the face and/or trunk in patients aged 9 years and older, and warns about local irritation and ultraviolet exposure. It does not establish superiority or lower irritation versus another retinoid.
U.S. prescribing indication for acne, skin irritation safety, ultraviolet-exposure precautions · 0.005% trifarotene cream
DailyMed prescribing information, 2023

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongUrea · applied to skin

Full record

5% urea moisturisers helped eczema-prone skin stay relapse-free longer, while reviews distinguish moisturising use at up to 10% from stronger keratolytic use above 10%.

Studied as Urea: 5% urea barrier-improving cream, reference moisturising cream, urea-containing barrier moisturiser, no maintenance treatment, 5% urea cream, four other experimental moisturisers, urea-containing topical formulations at 10% or less, urea-based preparations above 10%.

The trials studied complete moisturiser formulas, mostly as maintenance after eczema had cleared; they do not prove that every urea product performs the same way.

Sources · 4

Six-month multicentre randomized double-blind controlled trial in atopic dermatitis: the 5% urea cream reduced relapse risk by 37% versus a reference moisturiser and prolonged median time to relapse from 15 to 22 days.
eczema relapse risk, time to relapse · 5% urea barrier-improving cream, reference moisturising cream
Acta Derm Venereol, 2015
Randomized 26-week maintenance study in 44 people whose atopic eczema had cleared: 68% using the urea moisturiser remained relapse-free versus 32% with no treatment; median time to relapse was more than 180 versus 30 days.
relapse-free maintenance, time to relapse · urea-containing barrier moisturiser, no maintenance treatment
J Eur Acad Dermatol Venereol, 2009
Seven-week randomized forearm study in 78 volunteers: the ordinary 5% urea cream decreased transepidermal water loss and reduced susceptibility to an irritant, while some simplified moisturisers weakened barrier measures.
transepidermal water loss, irritant response · 5% urea cream, four other experimental moisturisers
Br J Dermatol, 2007
Clinical-literature review: urea formulations at 10% or less act mainly as moisturisers, while concentrations above 10% exert a keratolytic action.
moisturising action, keratolytic action · urea-containing topical formulations at 10% or less, urea-based preparations above 10%
Dermatol Ther, 2018

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateVitamin C (topical) · applied to skin

Full record

Studied in relation to brighter, more even-looking skin and collagen support over time. Formulation and freshness matter.

Sources · 2

Double-blind half-face trial: vitamin C side showed significant photoaging-score improvement at 12 weeks (cheeks P=0.006).
photoaging score
Dermatologic Surgery, 2002
Review: support for topical vitamin C in collagen synthesis, photoprotection (adjunct, not a sunscreen) and pigmentation.
collagen synthesis, photoprotection, pigmentation
Dermatologic Surgery, 2005

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedZinc · applied to skin

Full record

Limited but consistent evidence in relation to calmer, clearer skin. More supportive than central.

Sources · 2

Systematic review and meta-analysis: acne patients had significantly lower serum zinc; zinc reduced inflammatory papule counts as mono- or adjunct therapy.
inflammatory papule count, serum zinc
Dermatol Ther, 2020
Zinc has antibacterial/anti-inflammatory and sebum-reducing effects; recommendation strength B (limited-quality evidence).
acne, sebum
J Drugs Dermatol, 2013

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

MIRU

MIRU evidence library

Read the receipts.

See what was studied, how strong it is and where the evidence stops. Every entry below has at least one source you can open.

Check the formula

30 ingredients · 62 linked sources

Find a receipt

Evidence level

30 of 30 records

StrongNiacinamide · applied to skin

Full record

Well studied in relation to a calmer, more even-looking complexion and a supported skin barrier.

Studied as Niacinamide: 5% niacinamide.

Sources · 2

Double-blind split-face, 5% niacinamide, 12 weeks: significant reductions in fine lines, hyperpigmented spots, red blotchiness and sallowness; improved elasticity.
fine lines, hyperpigmented spots, red blotchiness, sallowness, elasticity · 5% niacinamide
Dermatologic Surgery, 2005
Confirmed reductions in yellowing, wrinkling, red blotchiness and hyperpigmented spots.
yellowing, wrinkling, red blotchiness, hyperpigmented spots
Int J Cosmetic Science, 2004

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongSunscreen / SPF · applied to skin

Full record

One of the best-studied things you can do in relation to keeping skin looking younger over time. The prevention step that’s hard to beat.

Studied as Sunscreen / SPF: broad-spectrum SPF 15+, daily.

Sources · 1

RCT, 4.5 years: daily-sunscreen group showed 24% less skin aging than discretionary use (OR 0.76, 95% CI 0.59–0.98).
skin aging · broad-spectrum SPF 15+, daily
Annals of Internal Medicine, 2013

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateCeramides · applied to skin

Full record

Studied in relation to a stronger, better-hydrated skin barrier. Part of the skin’s own lipid structure.

Sources · 2

Systematic review and meta-analysis in atopic dermatitis, five studies: ceramide-containing moisturisers improved SCORAD against other moisturisers (mean difference -0.98, P=0.003). Transepidermal water loss was NOT significantly different (-3.56, P=0.17, high heterogeneity).
atopic-dermatitis severity, transepidermal water loss
Indian J Dermatol, 2023
Randomised, investigator-blinded, intra-individual comparison in patients with controlled atopic dermatitis: a ceramide-precursor moisturiser on one lower leg against the untreated other leg for 4 weeks gave greater reduction in transepidermal water loss and clinical dryness and higher hydration (all P<.01).
transepidermal water loss, dryness, hydration
J Dermatolog Treat, 2013

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedRetinol (over the counter) · applied to skin

Full record

Studied in relation to fine lines and surface texture, with results that vary a lot between trials.

Studied as Retinol (over the counter): 0.4% retinol lotion.

Sources · 2

Systematic review of nine randomised trials: four found no significant difference between retinol and vehicle. The five that did gave weak evidence for a mild effect on fine wrinkle lines only, with major methodological flaws.
fine facial wrinkles
J Clin Aesthet Dermatol, 2021
Vehicle-controlled trial of 0.4% retinol in ARM skin, 24 weeks, in 36 residents of two senior citizen facilities, mean age 87: fine wrinkle scores improved against vehicle (-1.64 vs -0.08, P<.001), with higher glycosaminoglycan and procollagen I expression.
fine wrinkles, skin matrix synthesis · 0.4% retinol lotion
Arch Dermatol, 2007

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongAzelaic acid · applied to skin

Full record

Well studied in relation to calmer, clearer, more even-looking skin. And tends to be gentle.

Studied as Azelaic acid: 15–20% azelaic acid.

Sources · 1

15–20% azelaic acid gave meaningful improvement across acne, rosacea and melasma; 20% comparable to hydroquinone for melasma.
acne, rosacea, melasma · 15–20% azelaic acid
J Cosmet Dermatol (43-trial review), 2023

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedSalicylic acid (BHA) · applied to skin

Full record

Studied in relation to clearer, less congested skin. Most of the record is in-clinic peels rather than the products on a shelf.

Studied as Salicylic acid (BHA): leave-on topical, in-clinic chemical peel.

Sources · 3

Cochrane review: for people rating their own acne there may be little or no difference between salicylic acid and tretinoin, on low-quality evidence from 46 participants. Risk of bias and imprecision limit confidence.
acne · leave-on topical
Cochrane Database Syst Rev, 2020
Review of salicylic acid AS A PEELING AGENT: its comedolytic action makes it a useful peel for acne across skin types. It does not study leave-on products.
acne, comedones · in-clinic chemical peel
Clin Cosmet Investig Dermatol, 2015
Peel RCT: reduced non-inflammatory lesions (~48.5% from baseline by Day 98).
non-inflammatory acne lesions · in-clinic chemical peel
J Cosmet Dermatol, 2011

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongAdapalene · applied to skin

Full record

Well studied in relation to clearer skin, most often alongside benzoyl peroxide.

Studied as Adapalene: adapalene with benzoyl peroxide.

Sources · 1

Systematic review of 8 randomised controlled trials, 4,596 participants, compared against vehicle or single-agent treatment: acne lesion reduction ranged from 27.5% to 70.2%, and the review concludes the combination is safe and effective. Adverse effects ranged from 2.7% to 57.9% and were mild.
acne · adapalene with benzoyl peroxide
Cureus, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateAHAs (glycolic/lactic) · applied to skin

Full record

Studied in relation to smoother, more refined-looking skin over time.

Studied as AHAs (glycolic/lactic): 8% glycolic cream, 8% lactic cream.

Sources · 2

Vehicle-controlled: 8% glycolic and 8% lactic creams improved photodamage in 76%/71% of facial sides vs 40% vehicle.
photodamage · 8% glycolic cream, 8% lactic cream
Archives of Dermatology, 1996
AHAs produced ~25% increase in skin thickness with epidermal and dermal remodelling.
skin thickness, dermal remodelling
J Am Acad Dermatol, 1996

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateBakuchiol · applied to skin

Full record

Studied as Bakuchiol: 0.5% bakuchiol cream twice daily, 0.5% retinol cream once daily, bakuchiol alone or in combination formulas, genistein, bakuchiol, vitamins and ceramides combination product.

Sources · 3

Randomized double-blind head-to-head study in 44 people over 12 weeks: both groups improved from baseline on wrinkle surface area and hyperpigmentation, with no statistically significant difference between groups; retinol users reported more scaling and stinging. There was no vehicle arm and the schedules differed.
wrinkle surface area, hyperpigmentation, scaling, stinging · 0.5% bakuchiol cream twice daily, 0.5% retinol cream once daily
Br J Dermatol, 2019
Systematic review of 29 included reports found 16 preclinical studies and seven clinical studies; the evidence base was predominantly preclinical and the authors called for additional rigorous controlled human trials.
photoageing, acne, post-inflammatory hyperpigmentation, adverse events · bakuchiol alone or in combination formulas
J Cosmet Dermatol, 2022
Randomized double-blind placebo-controlled trial in 80 men over 12 weeks: the combination modestly improved lightness, colour evenness, spots and some roughness measures, but not melanin, erythema, acne or elasticity. Bakuchiol was not tested alone.
skin lightness, colour evenness, spots, roughness, melanin, erythema, acne, elasticity · genistein, bakuchiol, vitamins and ceramides combination product
Skin Res Technol, 2026

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongBenzoyl peroxide · applied to skin

Full record

Well studied in relation to clearer skin. A long-standing, dermatologist-backed option for breakouts.

Studied as Benzoyl peroxide: adapalene with benzoyl peroxide.

Sources · 1

Systematic review of 8 randomised controlled trials, 4,596 patients, compared against vehicle or single-agent treatment: acne lesion reduction ranged from 27.5% to 70.2%, and the review concludes the combination is safe and effective. It also states that combining a retinoid with benzoyl peroxide does not contribute to antibiotic resistance.
acne · adapalene with benzoyl peroxide
Cureus, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedCentella asiatica (cica) · applied to skin

Full record

Encouraging early evidence in relation to calmer, more comfortable skin. A long-used soothing botanical.

Studied as Centella asiatica (cica): standardised Centella extract, madecassoside.

Sources · 2

Review of topical Centella asiatica. The one controlled human result it reports for erythema is a split-face, double-blind, placebo-controlled trial of 0.05% standardised ECa 233 gel after laser resurfacing for acne scars, in which erythema subsided by day 7 against day 28 on the placebo side (Damkerngsuntorn et al. 2020). The review also describes the actives enhancing collagen synthesis and modulating inflammation.
post-laser erythema, collagen synthesis · standardised Centella extract
Pharmaceutics, 2024
Madecassoside facilitated wound healing via antioxidative activity and collagen synthesis (pre-clinical).
wound healing · madecassoside
J Ethnopharmacol, 2008

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongColloidal oatmeal · applied to skin

Full record

A complete 1% colloidal oatmeal cream was non-inferior to a named prescription barrier cream over three weeks in 90 children with mild-to-moderate atopic dermatitis.

Sources · 3

Double-blind randomized active-controlled study in 90 children over three weeks: the complete 1% colloidal oatmeal cream was non-inferior to the prescription barrier cream for EASI, using a prespecified 1.5-point non-inferiority margin.
eczema area and severity index, itch, global atopic-dermatitis assessment · complete 1% colloidal oatmeal cream, ceramide-based prescription barrier cream
J Dermatolog Treat, 2017
Double-blind randomized study with 50 completers: both groups improved during the two-week fluocinolone lead-in; during the following four weeks, the oatmeal arm held improvement while symptoms in the base-cream arm returned toward baseline.
hand eczema severity, itch, dermatology life quality index · fluocinolone 0.025% for two weeks followed by 1% colloidal oatmeal cream, fluocinolone 0.025% for two weeks followed by base cream
Clin Cosmet Investig Dermatol, 2020
The US OTC skin-protectant monograph names colloidal oatmeal itself as an active ingredient at a minimum 0.007%, or 0.003% when combined with mineral oil under the specified monograph condition.
skin-protectant regulatory status · colloidal oatmeal at 0.007% minimum, colloidal oatmeal at 0.003% minimum with mineral oil
FDA OTC Monograph M016, 2021

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateEctoin · applied to skin

Full record

Short clinical studies of ectoin-containing creams reported improved eczema severity scores; the vehicle-controlled trial used ectoin together with hyaluronic acid.

Sources · 3

Randomized intra-individual double-blind multicentre trial in 65 adults with mild-to-moderate atopic dermatitis: after 28 days, the ectoin-containing cream performed equivalently to an active nonsteroidal reference cream. There was no plain-vehicle arm.
local eczema severity, investigator assessment, itch · ectoin-containing cream EHK02-01, nonsteroidal anti-inflammatory reference cream
Skin Pharmacol Physiol, 2014
Randomized observer-blind vehicle-controlled four-week trial in children aged 2–18: 70 were randomized and 57 analysed; the combination cream improved objective SCORAD versus vehicle (P < .001), but ectoin was not tested alone. Mild cutaneous adverse events occurred in 23.5% versus 5.7%.
objective SCORAD, investigator assessment, itch, cutaneous adverse events · 1% ectoine with 0.1% hyaluronic acid cream, vehicle cream
Pediatr Dermatol, 2023
Systematic review of six clinical studies (five in atopic dermatitis, one in retinoid dermatitis): outcomes generally favoured ectoin-containing formulations, but many studies were open-label, adjunctive or low-certainty and one author was employed by Bitop AG.
skin dryness, itch, dermatitis severity · 5.5–7% ectoin-containing topical formulations
Dermatol Ther (Heidelb), 2022

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedFerulic Acid · applied to skin

Full record

Small human studies found less UV-related redness and damage markers after four days with complete antioxidant combinations containing ferulic acid.

Sources · 3

Porcine-skin study: adding 0.5% ferulic acid stabilized the vitamin C and E formula and increased its reported photoprotection from about fourfold to about eightfold. This was pig, not human, skin and did not test ferulic acid alone.
formula stability, erythema, sunburn cells, thymine dimers · 15% L-ascorbic acid with 1% alpha-tocopherol, the same formula with 0.5% ferulic acid
J Invest Dermatol, 2005
Small human in-vivo study over four days: the complete vitamin C, vitamin E and ferulic acid formula reduced several solar-simulated-radiation damage markers versus vehicle. The abstract did not report the sample size, and ferulic acid was not isolated.
erythema, sunburn cells, thymine dimers, p53, inflammatory cytokines · 15% L-ascorbic acid with 1% alpha-tocopherol and 0.5% ferulic acid, vehicle
J Am Acad Dermatol, 2008
Randomized four-day human study in 10 participants: the complete vitamin C, ferulic acid and phloretin formula reduced several UV-related damage markers versus vehicle. Ferulic acid was not tested alone, and one author was affiliated with L’Oreal USA.
erythema, sunburn cells, thymine dimers, MMP-9, p53, Langerhans cells · vitamin C with ferulic acid and phloretin, vehicle
J Cosmet Dermatol, 2009

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongGlycerin · applied to skin

Full record

Human studies of complete creams found that 20% glycerin increased measured skin hydration; effects on other endpoints depended on the formulation.

Sources · 3

Bilateral randomized double-blind study in 17 healthy volunteers over 10 days: the 20% glycerin cream increased measured skin hydration versus vehicle, but did not improve transepidermal water loss or the response to sodium lauryl sulphate.
skin hydration, transepidermal water loss, sodium lauryl sulphate irritation response · 20% glycerin cream, vehicle cream
Int J Cosmet Sci, 2001
Randomized double-blind study in 197 people with atopic dermatitis over 30 days: dryness improved equally with the glycerin and urea/saline creams; moderate or severe smarting was reported by 10% with glycerin versus 24% with urea/saline.
dryness, smarting · 20% glycerin cream, cream base without glycerin, 4% urea plus 4% sodium chloride cream
Acta Derm Venereol, 2002
Randomized double-blind four-arm crossover study in 51 people measured over 12 hours: the complete emollient outperformed vehicle; the glycerol component contributed to hydration while petrolatum contributed to the transepidermal-water-loss effect.
transepidermal water loss, corneometry · glycerol plus petrolatum emollient, vehicle, vehicle plus glycerol, vehicle plus petrolatum
J Cosmet Dermatol, 2020

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateHyaluronic acid (topical) · applied to skin

Full record

One 60-day, 0.1% periocular study reported hydration and elasticity improvements across the tested molecular weights; wrinkle-depth improvement was limited to the 50 and 130 kDa arms.

Studied as Hyaluronic acid (topical): 0.1% hyaluronan at 50, 130, 300, 800 or 2,000 kDa.

Sources · 1

Split-area, vehicle-controlled study in 76 women over 60 days: all five 0.1% periocular hyaluronan preparations improved measured hydration and elasticity versus vehicle; wrinkle-depth improvement was reported only for the 50 and 130 kDa arms. The paper’s penetration explanation is speculative, not a demonstrated outcome.
periocular hydration, periocular elasticity, periocular wrinkle depth · 0.1% hyaluronan at 50, 130, 300, 800 or 2,000 kDa
J Drugs Dermatol, 2011

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedKojic Acid · applied to skin

Full record

Sources · 2

Randomized single-blind, single-centre study in 80 people over 12 weeks: the kojic-acid and hydroquinone combination had the greatest decrease in melasma severity, followed by the triple combination and kojic acid alone; every arm contained kojic acid and there was no vehicle control.
melasma area and severity index · 1% kojic acid cream, 1% kojic acid + 2% hydroquinone cream, 1% kojic acid + 0.1% betamethasone valerate cream, 1% kojic acid + 2% hydroquinone + 0.1% betamethasone valerate cream
Indian J Dermatol, 2013
Split-face randomized evaluator-blinded pilot in 30 people over 12 weeks plus four weeks follow-up: melanin-index and modified-MASI changes did not differ between the alpha-arbutin/kojic-acid cream and triple therapy; physician assessment improved only on the triple-therapy side, while recurrence severity, erythema and stinging were higher there. Kojic acid was not tested alone.
melanin index, modified melasma area severity index, physician global assessment, recurrence, adverse effects · 5% alpha-arbutin + 2% kojic acid cream, triple combination cream
J Cosmet Dermatol, 2025

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedKTTKS (Lys-Thr-Thr-Lys-Ser) · applied to skin

Full record

The held evidence is an ex-vivo stability and distribution study of the exact KTTKS sequence in hairless-mouse skin.

Studied as KTTKS (Lys-Thr-Thr-Lys-Ser): KTTKS, palmitoyl-KTTKS.

Unmodified KTTKS was absent from every measured skin layer and from receptor solution. The Palmitoyl Pentapeptide-4 clinical literature does not transfer to KTTKS.

Sources · 1

Ex-vivo full-thickness hairless-mouse skin: neither KTTKS nor pal-KTTKS reached receptor solution. Unmodified KTTKS was absent from the measured skin layers, while pal-KTTKS was detected in stratum corneum and epidermis with a small dermal amount. This does not establish human permeation or a clinical effect for KTTKS.
ex-vivo hairless-mouse skin distribution, dermal stability · KTTKS, palmitoyl-KTTKS
Biomol Ther (Seoul), 2014

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedLiquiritin · applied to skin

Full record

One small four-week split-face controlled trial in 20 women with epidermal melasma reported improvement with 1% liquiritin cream versus vehicle.

Studied as Liquiritin: 1% liquiritin cream.

Sources · 1

Twenty women with bilateral epidermal melasma used liquiritin cream on one side of the face and vehicle on the other twice daily for four weeks. The report describes improvement with 1% liquiritin, but the PubMed abstract does not state randomization or blinding and names no active comparator.
epidermal melasma pigmentation · 1% liquiritin cream
Int J Dermatol, 2000

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedPalmitoyl Pentapeptide-4 (pal-KTTKS) · applied to skin

Full record

The held evidence is specific to Palmitoyl Pentapeptide-4 (pal-KTTKS), not to peptides as a class.

Studied as Palmitoyl Pentapeptide-4 (pal-KTTKS): KTTKS, palmitoyl-KTTKS, Palmitoyl Pentapeptide-4.

Sources · 2

Ex-vivo full-thickness hairless-mouse skin: neither KTTKS nor pal-KTTKS reached receptor solution. KTTKS was absent from the measured skin layers; pal-KTTKS was detected in stratum corneum and epidermis, with a small dermal amount. This is animal-skin distribution evidence, not human permeation.
ex-vivo hairless-mouse skin distribution, dermal stability · KTTKS, palmitoyl-KTTKS
Biomol Ther (Seoul), 2014
Narrative review names Palmitoyl Pentapeptide-4 as the well-researched molecule and cites Robinson et al. 2005 for a controlled study in photoaged human facial skin. It does not establish a result for peptides as a class.
narrative review of topical peptide treatments · Palmitoyl Pentapeptide-4
Cosmetics, 2017

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModeratePanthenol (pro-vitamin B5) · applied to skin

Full record

Studied in relation to soothed, better-hydrated skin. A gentle barrier supporter.

Studied as Panthenol (pro-vitamin B5): panthenol emollient.

Sources · 2

Topical dexpanthenol acts as a humectant and barrier enhancer, increasing stratum-corneum hydration.
stratum-corneum hydration, barrier function
Am J Clin Dermatol, 2002
Two RCTs: panthenol emollient improved hydration and barrier-restoration vs control.
hydration, barrier restoration · panthenol emollient
J Dermatolog Treat, 2017

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateRetinaldehyde · applied to skin

Full record

Two small controlled studies found retinaldehyde improved fine lines or skin elasticity versus a plain cream, with less irritation than retinoic acid.

Studied as Retinaldehyde: 0.05% retinaldehyde cream, 0.05% retinoic acid cream, vehicle cream.

Both controlled studies are more than 25 years old; samples were small and several secondary measurements did not improve.

Sources · 2

Randomized vehicle-controlled trial in 125 people over 44 weeks: retinaldehyde and retinoic acid improved wrinkle and roughness measures while vehicle did not; retinoic acid was more irritating than retinaldehyde.
wrinkle profilometry, skin roughness, tolerability · 0.05% retinaldehyde cream, 0.05% retinoic acid cream, vehicle cream
J Am Acad Dermatol, 1998
One-year controlled study in 40 people: retinaldehyde increased epidermal thickness and elasticity versus control, while dermal thickness and stiffness did not significantly change.
epidermal thickness, skin elasticity, dermal thickness, skin stiffness · 0.05% retinaldehyde cream
Dermatology, 1999

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongRetinoids (class) · applied to skin

Full record

Topical retinoids as a class are among the most studied ingredients for skin texture over time.

Studied as Retinoids (class): adapalene with benzoyl peroxide.

Sources · 1

The review names retinoids, antibiotics and benzoyl peroxide as the main treatment options for acne, and states that a retinoid with benzoyl peroxide is safe and effective without contributing to antibiotic resistance. (Its own trial data is eight adapalene/benzoyl-peroxide trials and is adapalene/BPO specific.)
acne · adapalene with benzoyl peroxide
Cureus, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedSnail Secretion Filtrate · applied to skin

Full record

One small placebo-controlled trial found fewer inflammatory lesions with a three-ingredient serum containing snail secretion filtrate.

Studied as Snail Secretion Filtrate: snail secretion filtrate, calendula and licorice serum, placebo serum, snail mucin and snail extract preparations.

Sources · 2

Twelve-week randomized double-blind placebo-controlled trial in 66 people with mild-to-moderate mask-related acne: the three-ingredient serum reduced inflammatory lesions more than placebo, while non-inflammatory lesions and measured skin biophysics did not significantly differ. Snail secretion filtrate was not tested alone.
inflammatory acne lesions, non-inflammatory acne lesions, sebum, corneometry, transepidermal water loss, erythema · snail secretion filtrate, calendula and licorice serum, placebo serum
J Cosmet Dermatol, 2022
Literature review of medical and cosmetic uses: most studies were preclinical or small clinical studies, and larger clinical trials are needed to support claimed benefits and clarify safety and ethical-extraction questions.
clinical evidence limitations, allergy investigation, ethical extraction · snail mucin and snail extract preparations
J Cosmet Dermatol, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedTranexamic Acid · applied to skin

Full record

One small vehicle-controlled trial found 5% topical tranexamic acid no better than its vehicle after 12 weeks and reported more redness.

Sources · 3

Double-blind 12-week split-face trial: 23 women enrolled and 21 completed. The 5% tranexamic acid side was neither superior nor different from vehicle for pigmentation, while erythema was significantly higher on the tranexamic-acid side.
melanin index, melasma severity, erythema · 5% topical tranexamic acid gel, vehicle gel
J Cosmet Laser Ther, 2012
Systematic review and meta-analysis of 22 randomised trials with 1,280 patients. Oral treatment showed the largest pooled MASI decrease, followed by injections and topical applications; studies had high heterogeneity, especially among combination treatments.
melasma severity, adverse effects · oral tranexamic acid, injected tranexamic acid, topical tranexamic acid
J Dermatolog Treat, 2024
Randomised double-blind 99-person comparison of two tranexamic-acid and niacinamide combination creams with 4% hydroquinone. Because neither test cream isolated tranexamic acid and the comparator was active, the trial does not establish tranexamic acid alone or prove equivalence.
melanin index, melasma severity, quality of life, adverse reactions, relapse · 2% tranexamic acid with 2% niacinamide niosomal cream, 5% tranexamic acid with 4% niacinamide conventional cream, 4% hydroquinone cream
Sci Rep, 2025

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongTretinoin · applied to skin

Full record

Well studied in relation to fine lines, mottled pigmentation and surface texture over months of use.

Tretinoin is a prescription medicine in most countries, and irritation early on is the usual reason people stop. Someone who can see your skin should hold the plan.

Sources · 3

Seven randomised controlled trials: all reported topical tretinoin improving the clinical appearance of photoaging (wrinkling, mottled hyperpigmentation, sallowness and lentigines) as early as 1 month, and still present after 24 months.
photoaging, wrinkling, mottled hyperpigmentation, sallowness, lentigines
Int J Womens Dermatol, 2022
Meta-analysis of eight trials and 1,361 patients: topical tretinoin significantly improved both fine and coarse facial wrinkles from photodamage.
fine wrinkles, coarse wrinkles
Dermatol Pract Concept, 2025
AAD acne guideline: strong recommendations for topical retinoids alongside benzoyl peroxide, topical antibiotics and oral doxycycline. Acne, not photoaging.
acne vulgaris
J Am Acad Dermatol, 2024

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongTrifarotene (prescription topical) · applied to skin

Full record

Two 12-week randomized, double-blind, vehicle-controlled phase 3 trials found greater facial and truncal acne improvement with trifarotene 0.005% cream than vehicle.

Studied as Trifarotene (prescription topical): 0.005% trifarotene cream.

Sources · 2

Two separate 12-week randomized, double-blind, vehicle-controlled phase 3 trials in patients aged 9 years or older found trifarotene 0.005% cream superior to vehicle on investigator success and inflammatory and non-inflammatory lesion counts on the face and trunk. The author list included employees of Galderma R&D.
facial acne vulgaris, truncal acne vulgaris · 0.005% trifarotene cream
J Am Acad Dermatol, 2019
The current U.S. prescribing information, revised October 2023, indicates topical 0.005% trifarotene cream for acne vulgaris on the face and/or trunk in patients aged 9 years and older, and warns about local irritation and ultraviolet exposure. It does not establish superiority or lower irritation versus another retinoid.
U.S. prescribing indication for acne, skin irritation safety, ultraviolet-exposure precautions · 0.005% trifarotene cream
DailyMed prescribing information, 2023

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

StrongUrea · applied to skin

Full record

5% urea moisturisers helped eczema-prone skin stay relapse-free longer, while reviews distinguish moisturising use at up to 10% from stronger keratolytic use above 10%.

The trials studied complete moisturiser formulas, mostly as maintenance after eczema had cleared; they do not prove that every urea product performs the same way.

Sources · 4

Six-month multicentre randomized double-blind controlled trial in atopic dermatitis: the 5% urea cream reduced relapse risk by 37% versus a reference moisturiser and prolonged median time to relapse from 15 to 22 days.
eczema relapse risk, time to relapse · 5% urea barrier-improving cream, reference moisturising cream
Acta Derm Venereol, 2015
Randomized 26-week maintenance study in 44 people whose atopic eczema had cleared: 68% using the urea moisturiser remained relapse-free versus 32% with no treatment; median time to relapse was more than 180 versus 30 days.
relapse-free maintenance, time to relapse · urea-containing barrier moisturiser, no maintenance treatment
J Eur Acad Dermatol Venereol, 2009
Seven-week randomized forearm study in 78 volunteers: the ordinary 5% urea cream decreased transepidermal water loss and reduced susceptibility to an irritant, while some simplified moisturisers weakened barrier measures.
transepidermal water loss, irritant response · 5% urea cream, four other experimental moisturisers
Br J Dermatol, 2007
Clinical-literature review: urea formulations at 10% or less act mainly as moisturisers, while concentrations above 10% exert a keratolytic action.
moisturising action, keratolytic action · urea-containing topical formulations at 10% or less, urea-based preparations above 10%
Dermatol Ther, 2018

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

ModerateVitamin C (topical) · applied to skin

Full record

Studied in relation to brighter, more even-looking skin and collagen support over time. Formulation and freshness matter.

Sources · 2

Double-blind half-face trial: vitamin C side showed significant photoaging-score improvement at 12 weeks (cheeks P=0.006).
photoaging score
Dermatologic Surgery, 2002
Review: support for topical vitamin C in collagen synthesis, photoprotection (adjunct, not a sunscreen) and pigmentation.
collagen synthesis, photoprotection, pigmentation
Dermatologic Surgery, 2005

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.

LimitedZinc · applied to skin

Full record

Limited but consistent evidence in relation to calmer, clearer skin. More supportive than central.

Sources · 2

Systematic review and meta-analysis: acne patients had significantly lower serum zinc; zinc reduced inflammatory papule counts as mono- or adjunct therapy.
inflammatory papule count, serum zinc
Dermatol Ther, 2020
Zinc has antibacterial/anti-inflammatory and sebum-reducing effects; recommendation strength B (limited-quality evidence).
acne, sebum
J Drugs Dermatol, 2013

Affiliation note. Publication links report the study authors and their affiliations. MIRU does not infer independence from an affiliation alone.