Does mandelic acid work for acne?
Short answer
Probably, as a professional peel. In small trials, a 45% mandelic acid peel worked about as well as a salicylic acid peel for mild to moderate acne. We found no good trial of a leave-on mandelic acid serum, so the peel results may not apply to products you buy, and the evidence for dark spots is weak.
Does a mandelic acid peel help acne?
Probably: small trials found it helped mild to moderate acne.
In 50 people, a 45% mandelic acid peel worked about as well as a 30% salicylic acid peel over 12 weeks, with fewer side effects reported. In a three-peel trial, a 10% mandelic plus 20% salicylic peel cut acne scores 74%, similar to a glycolic peel at 71%. All were in-clinic peels.
Studies:Dayal 2020Sarkar 2019
Do mandelic acid serums work like the peels?
Unknown: nearly all the evidence is for clinic peels.
The studies used professional peels of 30% or more (45% in the main acne trial), left on for minutes and washed off. We found no placebo-controlled trial of a leave-on mandelic acid product for acne or dark spots, so peel results do not carry over to a serum.
Studies:Garofalo 2019Jeon 2025
Is mandelic acid better than salicylic or glycolic acid?
No clear winner: the trials found similar results.
The 45% peel and a 30% salicylic peel did about equally; mandelic did better on inflamed spots and salicylic on non-inflamed ones. A combination peel and a glycolic peel both cut acne scores about 70%. Two reviews call the evidence low quality and could not name a best peel.
Does mandelic acid fade dark spots?
Weak evidence: no trial tests it alone for dark spots.
In the one melasma trial, a mandelic and salicylic peel did about as well as a glycolic peel, but everyone also used hydroquinone and tretinoin. A 30% mandelic peel for dark circles helped, but a lactic acid peel did better. We found no trial of a leave-on product for pigment.
Studies:Sarkar 2016Malviya 2025Jeon 2025
Is mandelic acid gentle on skin?
Mild in trials, though irritation was common in one.
With the combination peel, burning affected 2 of 15 people and brief redness 1 of 15. A 30% mandelic peel for dark circles caused irritation in 28.6% of people, against 14.3% with lactic acid. We found no data on long-term use or on leave-on irritation.
Studies:Sarkar 2019Malviya 2025
How strong is the evidence?
Low: small trials, mostly of peels, mostly unblinded.
The trials had 15 to 90 people and ran 6 to 20 weeks, mostly in India, and most did not describe blinding. Reviews of acne peels, including a Cochrane review, call the evidence low quality and found no peel clearly better. Nothing tests long-term results.
Studies:Chen 2018Liu (Cochrane) 2020
See what Reddit recommends for acne →
Products Reddit recommends with mandelic acid
Ranked by how often Reddit recommends them. The studies used professional peels of 30% or more, not leave-on products, so a serum is a different treatment. Check a product’s label for its percentage.
Skin Perfecting 6% Mandelic Acid + 2% Lactic Acid Liquid Exfoliant
See alternativesThe why
Tretinoin off-days are when people leave this toner on for about an hour, then increase contact time gradually.
The why
Tolerance-builders start once weekly, using it as their first step before moving up to stronger exfoliants.
Mandelic Acid Exfoliating & Clearing Serum
See alternativesThe why
Rosacea routines turn to gentler exfoliation when most AHAs aren’t tolerable.
The why
At five percent, this toner pairs mandelic acid with beta-glucan and panthenol.
Soft Touch AHA, a 10% Mandelic Acid Gel
See alternativesThe why
Three-to-six-times-weekly use feels gentle, with no oily or greasy finish.
See all 7 mandelic acid products Compare alternatives to Skin Perfecting 6% Mandelic Acid + 2% Lactic Acid Liquid Exfoliant
8 studies we read for this page
The answers above rest on these mandelic acid papers. We checked each one’s design, size and result against its PubMed record or full text. Acne and melasma scores are clinician ratings; lower is better. A peel is a strong acid applied by a clinician and washed off after a few minutes.
Acne: peel trials
Peel ≈ salicylic acid peelDayal et al. (2020) (opens PubMed in a new tab)J Cosmet Dermatol
Almost equal efficacy, with no significant difference in acne score. Salicylic acid did better on non-inflammatory lesions, mandelic acid on inflammatory ones. Adverse effects were lesser with the mandelic peel (no rates given).
Combo peel cut acne score ~74%Sarkar et al. (2019) (opens PubMed in a new tab)J Cutan Aesthet Surg
Acne scores fell 74.1% with the salicylic-mandelic peel, 70.6% with glycolic and 69.7% with phytic; all three were effective. With the salicylic-mandelic peel, burning affected 2 of 15 and redness 1 of 15.
Dark spots and circles
Melasma: peel ≈ glycolic peelSarkar et al. (2016) (opens PubMed in a new tab)Dermatol Surg
MASI fell 61.0% with the salicylic-mandelic peel and 62.4% with glycolic (no significant difference), and 44.7% with the phytic peel. With no peel-free comparison, it cannot show what the peel added.
Lactic acid peel did betterMalviya et al. (2025) (opens PubMed in a new tab)Indian Dermatol Online J
Both improved, with no significant difference in grading. More people on lactic acid improved over 30% on a visual scale (50% vs 19%, p = 0.012) and satisfaction was higher. Irritation: 28.6% mandelic vs 14.3% lactic.
Leave-on products
Only 1% in a multi-active creamGarofalo et al. (2019) (opens PubMed in a new tab)Clin Cosmet Investig Dermatol
Acne scores fell 69% over 12 weeks. Because benzoyl peroxide and retinol were in the same cream, the result cannot be credited to mandelic acid.
Lab and forearm study onlyJeon et al. (2025) (opens PubMed in a new tab)Skin Res Technol
Skin brightness rose 6.7% with the ampoule and 6.1% on untreated skin, so the gap was small. The authors work for the product’s manufacturer, and the volunteers did not have melasma.
Reviews
Review: low-quality evidenceChen et al. (2018) (opens PubMed in a new tab)BMJ Open
Common peels seemed similarly effective for mild to moderate acne, and a robust conclusion that any peel is better could not be drawn. Quality ranged from very low to moderate.
Cochrane: low-quality evidenceLiu et al. (Cochrane) (2020) (opens PubMed in a new tab)Cochrane Database Syst Rev
Found there may be no difference between a glycolic peel and a salicylic-mandelic peel (one study, 40 people, low-quality evidence). Evidence for most comparisons was low or very low quality.
More acne research from PubMed (3)
Show 3 more studies from PubMed
A systematic review and network meta-analysis of topical pharmacological, oral pharmacological, physical and combined treatments for acne vulgaris.
The British journal of dermatology2022Meta-analysisPositive
In a large review of acne trials, chemical peels such as mandelic acid seemed to clear acne better than a placebo for mild-to-moderate acne, but the findings were uncertain.
Evidence-based topical treatments (azelaic acid, salicylic acid, nicotinamide, sulfur, zinc, and fruit acid) for acne: an abridged version of a Cochrane systematic review.
Journal of evidence-based medicine2020Systematic review3,880 participantsNeutral
In a large review of 3880 people with acne, a salicylic-mandelic acid treatment worked about as well as glycolic acid, but the review did not isolate mandelic acid’s effect.
Combination chemical peels are more effective than single chemical peel in treatment of mild-to-moderate acne vulgaris: A split face comparative clinical trial.
Journal of cosmetic dermatology2018Clinical trial45 participants10% mandelic acid in a salicylic acid and mandelic acid mixture peelPositive
In a trial of 45 people with mild-to-moderate acne, a peel using mandelic acid together with salicylic acid cleared acne better than a salicylic acid peel alone.
Research context, not treatment advice. Studies are about the ingredient, not any one product.
How we grade research for acne