Ci
Citric Acid
Citric AcidExfoliant
Technically an exfoliating acid, but it’s mostly there to set a product’s pH. A weaker exfoliant than glycolic or lactic acid.
What it does
On its own it exfoliates less than glycolic or lactic acid at the same strength. It also binds trace metals that would otherwise make a product break down.
The evidence, graded
expert consensusAdd an AHA and salicylic acid one at a time, within a safety panel's limits: AHAs under 10% at pH 3.5 or higher, salicylic acid under 3%. The review says salicylic acid is not a beta hydroxy acid and doesn't act like one, despite the label. In one study 10% glycolic acid made skin more sun-sensitive and 2% salicylic acid did not. No source Drop has read tested the two used together, so Drop can't tell you the pair is safe or that it isn't.Kornhauser 2010 · Clinical and Cosmetic Investigative 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.
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