Acetyl Mandelic Acid

Acetyl mandelic acid is a derivative of mandelic acid, an alpha-hydroxy acid (AHA) derived from bitter almonds. It functions primarily as a buffering agent in skincare formulations, helping to stabilise pH and moderate the strength of exfoliating products. By acetylating mandelic acid, manufacturers create a gentler version that releases the active compound more gradually on the skin.

As an exfoliating ingredient, acetyl mandelic acid works to dissolve the bonds between dead skin cells, promoting cellular turnover and revealing fresher skin beneath. Its larger molecular size compared to some other AHAs means it penetrates more slowly, which can make it suitable for those new to chemical exfoliation or with more reactive skin.

Acetyl mandelic acid is a prodrug, meaning it is gradually converted into mandelic acid once applied to the skin. This conversion happens slowly, which is the key to its gentler profile. Rather than delivering a high concentration of active acid all at once, the acetylated form releases mandelic acid incrementally, reducing the immediate irritation potential.

Once activated, mandelic acid works as a chemical exfoliant by breaking down the desmosomes—the 'glue' holding dead skin cells together. This allows the stratum corneum (the skin's outermost layer) to shed more efficiently. Additionally, the ingredient's buffering capacity helps maintain a skin-friendly pH in formulations, which is important for tolerability and efficacy of other actives.

Start with a low frequency—once or twice weekly—if you are new to chemical exfoliation, gradually increasing as your skin adapts. Apply to clean, dry skin and follow with a hydrating toner or essence to support your skin barrier. Because this ingredient supports cellular turnover, consistent use of a good broad-spectrum SPF 30+ during the day is essential, as exfoliated skin is more sun-sensitive. If combining with other actives, introduce them slowly and patch-test first.