Benefits: Anti-Aging, Evens Skin tone, Hydration
Categories: Exfoliant, Humectant, pH Adjuster/Stabilizer
- Can be extracted from milk or synthetically made
- Exfoliates the surface of skin
- Has hydrating properties and strengthens skin’s barrier
- Helps positively influence skin’s microbiome
Lactic acid is an alpha hydroxy acid (AHA) extracted from milk. Despite such natural origins, most forms used in cosmetics are synthetic because that form is easier to stabilize and formulate with, plus it’s vegan.
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.