Cited skincare — peer-reviewed evidence, no upsell.
Ma

Malic Acid

Malic AcidExfoliant

Fruit-derived AHA. Often blended with glycolic and lactic for layered exfoliation across multiple molecule sizes.

What it does

Malic acid is an AHA derived from apples. Larger and slower-penetrating than glycolic, smaller and faster than mandelic. It's almost always seen in blended-acid products rather than as the lead ingredient. The same AHA cautions apply: increases photosensitivity, can compound irritation when stacked with retinoids same-night.

The evidence, graded

strongAHAs (glycolic, lactic, mandelic) need an acidic pH (typically 3.5-4) to deliver advertised exfoliation. Products with neutral or partially neutralized pH still hydrate but won't drive meaningful keratolysis.Smith 1996 · Journal of the American Academy of Dermatology
strongAHAs and BHAs show texture and brightness improvements in 2-4 weeks. Deeper benefits — acne reduction, fine line softening, pigmentation lightening — take 8-12 weeks of consistent use.Smith 1996 · Journal of the American Academy of Dermatology

Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.

Also known as

apple acid

Pairs worth knowing

This page is public and indexed on purpose (unlike profiles and drops, which are unlisted) — it’s the citation behind shared ingredient cards, and it should be findable.
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