Quick answer
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 Key benefits: Anti-Aging, Evens Skin Tone, Hydration.
Lactic Acid
Updated
Propanoic acid, 2-hydroxy-
Purpose
This alpha hydroxy acid can be naturally derived from milk or lab-made, and helps skin shed dead cells on the surface so you’ll see fewer wrinkles and discolorations.
Rating
BEST
Category
Exfoliant, Humectant, pH Adjuster/Stabilizer
INCI Purpose
BUFFERING, HUMECTANT, SKIN CONDITIONING
Benefits
Alternative Names
Hair Profile
Functions
At a Glance
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
Article
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.
See: AHA
References