Lactic Acid

Lactic Acid Description

Lactic acid is an alpha hydroxy acid (AHA) that can be extracted from milk but those seeking to avoid animal-derived ingredients should know: Despite such natural origins, the lactic acid used in cosmetics is typically made via non-dairy fermentation, creating a bio-identical synthetic acid that’s easier to stabilize and formulate with, plus it’s vegan. This is the type of lactic acid Paula’s Choice Skincare uses.

In a pH-correct formula (ideally a pH between 3 and 4) and in concentrations between 5 and 12%, lactic acid exfoliates on the surface of skin. It does this by breaking down the material that holds dead skin together, allowing it to shed naturally as it once did. Lactic acid also has hydrating properties (as sodium lactate, it is part of skin’s natural moisturizing factor, or NMF).

In addition to these benefits, lactic acid strengthens skin’s barrier by encouraging it to make more ceramides, a key component of healthy skin. It also strongly influences skin’s microbiome, helping to keep its first line of defense strong by positively interacting with a neuropeptide in skin’s surface known as Substance P, resulting in quick diffusion of signs skin is stressed.

Like glycolic acid (another popular AHA), it helps brighten an uneven, dull skin tone.