Mandelic Acid: The Gentle AHA with the Large Molecule
Active Ingredients Glossary · M
INCI: Mandelic Acid
Mandelic acid is the gentle option among fruit acids. Its molecule is so large that it penetrates the skin only slowly—which makes it milder than glycolic acid and a good choice for anyone whose skin reacts sensitively to traditional exfoliants. It gets its name from bitter almonds, from which it was originally extracted.
What is mandelic acid?
Mandelic acid is an alpha hydroxy acid (AHA), just like glycolic and lactic acids. It was discovered during research into bitter almond extract, hence its name. For cosmetic use, it is typically produced synthetically today, which ensures consistent purity.
Its molecule is significantly larger than that of glycolic acid. As a result, it penetrates the skin more slowly and evenly and works primarily on the surface. It loosens the bonds between dead skin cells, allowing them to shed more easily. It is also slightly more fat-soluble than other AHAs, making it a good choice for combination skin and skin prone to breakouts.
Effect: What's Been Proven
Three out of five bars. It's easy to understand—and has been described in small studies, including comparisons with other acids—that mandelic acid, as an AHA, smooths the skin's surface and makes the complexion appear more even. These studies also show good tolerability. However, the studies are mostly small, and many examine professional peels at higher concentrations rather than at-home skincare products. Honest assessment: a gentle, well-tolerated acid—but less potent per application than glycolic acid.
Application & Combination
Like all AHAs, mandelic acid belongs in your evening routine: apply it to cleansed, dry skin, followed by a moisturizer. Start with one application per week and slowly increase to two or three. In ready-to-use products, mandelic acid is often part of a blend of acids. And even though it's mild, sunscreen is a must during the day, as AHAs temporarily make the skin more sensitive to light.
Good Combinations
✓ PHA (gluconolactone) – also gentle, helps lock in moisture
✓ Niacinamide – soothes and helps refine the skin
✓ Hyaluronic acid & ceramides – nourish the skin after exfoliation
Note
! Even mild acids increase sensitivity to light—be sure to use SPF during the day
! Do not combine with retinol or other exfoliants on the same evening
Mandelic Acid in the BONSANA Line
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Go to SKINCYCLOPEDIA →Frequently Asked Questions About Mandelic Acid
What is mandelic acid?
An alpha hydroxy acid that was originally discovered in bitter almond extract and is now mostly produced synthetically. It removes dead skin cells from the skin's surface, thereby smoothing the complexion.
What distinguishes mandelic acid from glycolic acid?
Its molecule is significantly larger. It penetrates more slowly, making it gentler and less likely to cause irritation. However, the effect per application is also less pronounced than with glycolic acid.
Do I need sunscreen when using mandelic acid?
Yes. Even mild AHAs make the skin temporarily more sensitive to light. During the day, sunscreen with an SPF of 30 or higher is essential during any acid treatment phase.
Can I combine mandelic acid with retinol?
Not on the same night. It's better to alternate—for example, use an acid one night and retinol another—so your skin isn't overwhelmed.
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