Ingredient guide
Salicylic acid
INCI name · salicylic acid
In short
Salicylic acid (also known as BHA) is a skincare acid generally associated with the look of pores, skin texture and smoothness and visible redness. It is often chosen for oily, combination and sensitive skin. MIRU describes it by what is visible on skin, never as a treatment or cure.
Skin type
Oily · Combination · Sensitive
Best used
Evening preferred for leave-on products
What it is
Salicylic acid is the canonical beta-hydroxy acid (BHA) and is widely used as a keratolytic and comedolytic active in cosmetic and dermatological products; mechanism: lipophilic phenolic acid with a pKa of 2.97 that penetrates sebum-filled follicles where AHAs cannot reach; breaks down desmosomes within the follicular infundibulum, loosening the compact cornified cells that form comedones; at 0.5-2% in leave-on formulations demonstrates comedolytic, anti-inflammatory, and mild antimicrobial activity; anti-inflammatory activity is mechanistically distinct from exfoliation. Salicylate moiety inhibits cyclooxygenase pathway prostaglandin synthesis, reducing follicular redness and post-inflammatory changes; has been studied in multiple RCTs for acne vulgaris and post-inflammatory hyperpigmentation; scalp use: 1-3% in rinse-off products is used for seborrhoeic dermatitis, scalp psoriasis, and dandruff via combination of keratolysis and anti-yeast properties; at low concentrations (0.5%) is well-tolerated on sensitive skin; penetration enhancer effect can amplify co-applied actives; recommended leave-on pH below 3.5 for maximum keratolytic activity while maintaining skin tolerance; oil-soluble nature enables formulation in anhydrous serums, cleansers, and scalp treatments.
Evidence receipt
LimitedSalicylic acid (BHA) · applied to skin
Based on 3 sources
Open the citable recordStudied 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.
See 3 sources
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, 2020Review 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, 2015Peel 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.
When to use it
Start leave-on salicylic acid in the evening, a couple of nights a week. Rinse-off cleansers can be used morning or evening if your skin tolerates them. Keep the rest of the routine gentle and use sunscreen during the day.
On the label
Usually 0.5–2% on labels
2% is the ceiling for most over-the-counter leave-on formulas.
Pairs well with
Give these space
The same rules the product checker and routine builder run. Friendly scheduling, not prohibitions.
Where it sits
An evening treatment step. After cleansing, before the heavier layers go on.
- Cleanse
- Salicylic acid
- Hydrate
- Moisturise
Also found as
Related
Compare products
Browse product comparisonsWhere to find it
Examples, not a ranking. A product lookup can confirm identity and background; a verdict still needs the full ingredient list.
SOME BY MI Bye Bye Blackhead 30 Days Miracle Green Tea Tox Bubble Cleanser
Salicylic acid cleanser built for daily use rather than a squeaky-clean finish.
COSRX BHA Blackhead Power Liquid
Betaine-salicylate BHA liquid for blackheads and congested pores.
Product comparisonSee the verdict and closest alternatives.Open comparisonThe Ordinary Salicylic Acid 2% Solution
A salicylic acid exfoliant works on a schedule, not on impulse. Less often reads better.
Product discovery is not efficacy proof. These examples are not ranked by commission.
Common questions
What does Salicylic acid do for skin?
Salicylic acid is associated in published research with the look of pores, skin texture and smoothness and visible redness. Salicylic acid is the canonical beta-hydroxy acid (BHA) and is widely used as a keratolytic and comedolytic active in cosmetic and dermatological products; mechanism: lipophilic phenolic acid with a pKa of 2.97 that penetrates sebum-filled follicles where AHAs cannot reach; breaks down desmosomes within the follicular infundibulum, loosening the compact cornified cells that form comedones; at 0.5-2% in leave-on formulations demonstrates comedolytic, anti-inflammatory, and mild antimicrobial activity; anti-inflammatory activity is mechanistically distinct from exfoliation. Salicylate moiety inhibits cyclooxygenase pathway prostaglandin synthesis, reducing follicular redness and post-inflammatory changes; has been studied in multiple RCTs for acne vulgaris and post-inflammatory hyperpigmentation; scalp use: 1-3% in rinse-off products is used for seborrhoeic dermatitis, scalp psoriasis, and dandruff via combination of keratolysis and anti-yeast properties; at low concentrations (0.5%) is well-tolerated on sensitive skin; penetration enhancer effect can amplify co-applied actives; recommended leave-on pH below 3.5 for maximum keratolytic activity while maintaining skin tolerance; oil-soluble nature enables formulation in anhydrous serums, cleansers, and scalp treatments. MIRU frames ingredients by what is visible, not by medical claims.
When should I use Salicylic acid?
Start leave-on salicylic acid in the evening, a couple of nights a week. Rinse-off cleansers can be used morning or evening if your skin tolerates them. Keep the rest of the routine gentle and use sunscreen during the day.
Is Salicylic acid suitable for my skin type?
Salicylic acid is often chosen for oily, combination and sensitive skin. It can be used with care. If your skin is reactive, patch-test first and watch for any irritation.
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Personal guidance, not medical advice.