Evidence recordApplied to skin
Kojic Acid
Answer
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.
Check the formulaEvidence grade
Limited
The record is early, small, indirect, mixed or tightly tied to one formulation.
Where it stops
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
Sources · 2
Source 1
Indian J Dermatol, 2013- Design
- Randomized single-blind study
- Participants
- 80
- Duration
- 12 weeks
- Measured outcome
- melasma area and severity index
- Studied formulation
- 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
Finding
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.
Source 2
J Cosmet Dermatol, 2025- Design
- Split-face randomized evaluator-blinded pilot
- Participants
- 30
- Duration
- 12 weeks
- Measured outcome
- melanin index, modified melasma area severity index, physician global assessment, recurrence, adverse effects
- Studied formulation
- 5% alpha-arbutin + 2% kojic acid cream, triple combination cream
Finding
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.