Common Name(s): Alpha-hydroxyphenylacetic acid,phenylglycolic acid
CAS Number: 90-64-2
DESCRIPTION
What It Does: Provides gentle aha exfoliation with lipophilic sebosuppressive anti-acne activity suitable for deeper skin tones.
Why It's Used: Skin-of-colour appropriate aha โ mandelic acid's large size reduces pih risk making it the preferred aha for fitzpatrick ivโvi skin tones.
How It Works: Larger mw (152 vs glycolic 76) provides slower penetration reducing irritation and post-inflammatory hyperpigmentation risk. benzene ring provides lipophilicity for better follicular penetration and sebum regulation. antibacterial vs p. acnes from phenolic structure.
Typically Found In: Skin-of-colour exfoliants,anti-acne for sensitive skin
TECHNICAL DETAILS
Primary Category: Active ingredient โ skin-of-colour appropriate aha
Secondary Functions: Brightening,collagen stimulation
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 1%โ15%
SOURCING & ETHICS
Vegan Status: Yes โ from bitter almond or synthetic
Halal Status: Yes
Source Notes: Fermentation-derived or synthetic. ph must be โค4.0 for aha activity.
SKIN COMPATIBILITY
Irritancy Rating: 2/5 โ low to moderate
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Photosensitizing โ mandatory spf use. start at low frequency.
Safe for Sensitive Skin: Use with caution โ spf required
SAFETY & COMPATIBILITY
Safety Profile: Safe at otc concentrations. eu: โค10% leave-on at ph โฅ3.5. mandatory spf advisory.
Works Well With: Niacinamide,ceramides,hyaluronic acid,spf
Avoid Combining With: Retinol in same step; multiple exfoliants simultaneously
SCIENTIFIC NOTE
Mandelic acid's safety advantage for darker skin tones arises from its slower penetration rate: the larger lipophilic molecule penetrates 2โ4ร more slowly than glycolic acid, reducing the risk of post-inflammatory hyperpigmentation from irritant-induced melanocyte stimulation โ a critical clinical consideration for fitzpatrick ivโvi skin.
Last Verified: 2026-03-12
Primary Sources: Cosing database,khunger & sacchidanand mandelic acid review