What Is Lactic Acid?

Lactic acid is an alpha hydroxy acid (AHA) that should be part of everyone’s routine. This is because AHAs increase exfoliation of the outer layer of skin, unclog pores, and function as a humectant to hydrate the skin. AHAs have further been shown to stimulate collagen and elastin production in the dermis. But what exactly is lactic acid and how does it differ from other AHAs? Are there any side effects to be concerned about? Read on for more info!

What’s an Alpha Hydroxy Acid?

Alpha hydroxy acids are a group of naturally occurring compounds that feature the hydroxyl (-OH) group in the α (alpha) position of the molecule (that is, attached to the carbon that is adjacent to the -COOH carbon). Alpha hydroxy acids commonly found in skincare products are glycolic acid or lactic acid.

What Is Lactic Acid and How Is It Different from Glycolic Acid?

Lactic acid, extracted from milk but usually found in synthetic form in most cosmetics

Lactic acid, extracted from milk but usually found in synthetic form in most cosmetics, is primarily used for out-of-office treatments. Lactic acid is great for wrinkle-reducing, wrinkle-refining, skin smoothing, and hydrating the skin. When used in concentrations of at least 10%, it’s a great addition that packs a terrific anti-aging punch.

Another advantage of lactic acid is that it does not temporarily thin the skin in the way that glycolic acid does, according to the Journal of the American Academy of Dermatology. Glycolic acid will increase skin thickness over time but lactic acid will not. Many choose lactic acid over glycolic acid and other agents that thin the skin – even temporarily – before flying, swimming, and especially during the warm summer months. Lactic acid is also great for hydrating the skin. Proof of lactic acid humectant abilities is that the only prescription drug FDA approved for dry skin is Lac-Hydrin, which has lactic acid (12%) as the main ingredient.

What Are the Side Effects?

Lactic acid treatments are highly effective and relatively gentle anti-aging treatments, but typically only when administered by a dermatologist

When administered by a licensed dermatologist, lactic acid treatments have been proven effective in fighting fine lines, dryness, and other signs of photoaging. Many at-home treatments have been associated with formulation-derived irritation and less efficacy when compared to other options. Lactic acid treatments are highly effective and relatively gentle anti-aging treatments, but typically only when administered by a dermatologist rather than via at-home treatments.