Ma
Malic Acid
Malic AcidExfoliant
An exfoliating acid from apples. There’s little research on it alone. Like glycolic acid, it makes skin more sun-sensitive.
What it does
It’s an exfoliating acid from apples. Its size is between glycolic and mandelic acid, so it goes in slower than glycolic. You’ll almost always see it in blends rather than as the main acid. Like glycolic acid, it makes skin more sun-sensitive. It can add to irritation on the same night as retinol.
The evidence, graded
strongBoth sources measured at one point: three months. Lactic acid twice a day for three months improved smoothness and the look of lines and wrinkles at 12%; at 5% it changed the surface and epidermis but not the dermis. Glycolic acid 20% twice a day for three months increased skin thickness and collagen gene expression. Neither reports an earlier timepoint. Both carry the sun caution too: glycolic acid 10%, six days a week for four weeks, raised UVB sensitivity.Smith 1996 · Journal of the American Academy of Dermatology ↗
expert consensusThe FDA says how much an AHA exfoliates depends on the type and strength of the acid, its pH, and the other ingredients. An industry safety panel judged glycolic and lactic acid safe at 10% or less with a pH of 3.5 or higher, to limit irritation. Lactic acid moisturizes better when it is partly or fully neutralized. No source Drop has read gives a pH below which an AHA starts to exfoliate.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
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