Aimed at softening and smoothing skin by gently but effectively exfoliating the top layer of skin, lactic acid can significantly improve the appearance of all skin types with regular use. It can be one of a few acids included in a clever serum or a brilliant mask, or be used as a standalone treatment swept on with a cotton pad. Here’s what you need to know, along with how to use it.
Key takeaways
- Lactic acid is a gentle chemical exfoliant that helps to refine skin texture, remove dead skin cells, and assist in efficient skin cell turnover.
- Lactic acid is sensitive skin-friendly, as well as being suitable for dry skin types.
- Lactic acid can help the skin to retain moisture, as well as gently exfoliating.
What is lactic acid?
Lactic acid is an exfoliant derived from the fermentation of lactose found in milk. You might recognize it as Cleopatra’s skincare ingredient of choice, although today’s sophisticated formulations mean there’s thankfully no need to bathe in sour milk in order to benefit.
An alpha hydroxy acid, or AHA for short, lactic acid is from the same family of acids as glycolic acid and mandelic acid, and, like them, is renowned for its ability to encourage cellular turnover and keep skin healthy and bright.
How does it work on the skin?
A water-soluble compound, lactic acid works by breaking down dead skin cells. “Lactic acid disrupts the bonds between dead skin cells in the outer layer of the skin, allowing them to be shed more easily,” explains Dr. Derrick Phillips, a dermatologist with CeraVe. “This process not only reveals fresher and more youthful-looking skin, but also helps to unclog pores.”
Because it’s a larger molecule than other AHAs, lactic acid can’t penetrate the skin as deeply, and so it’s ideal for more superficial exfoliation on the surface of the skin. As well as giving brightening benefits, that means it’s a great option for anyone with sensitive skin, as it doesn’t have as much potential to irritate.
What are the benefits of lactic acid?
Brighter skin
Skin brightening is one of the main benefits of using lactic acid, which means softer, smoother skin comes as standard, but it also plays a part in diminishing the appearance of fine lines and wrinkles. That’s because they’re often formed in the very top layers of skin, and once you eliminate those, you reveal the fresh, younger skin underneath.
Increased collagen production
“Lactic acid can stimulate production of collagen and structural molecules called glycosaminoglycans (GAGS),” adds Dr. Phillips, “which results in firmer and plumper skin with fewer fine lines and wrinkles.”
Help with acne and hyperpigmentation
The same is also true of shallow hyperpigmentation and even some spots and imperfections. “It has been shown to be effective at killing bacteria in the skin and some studies show it to be helpful in reducing acne lesions,” says Dr. Emma Craythorne, consultant dermatologist and Klira Founder, so look out for it in your spot treatments, too.
Effective hydration
Another major benefit of lactic acid is its ability to hydrate skin. Unlike other AHAs, lactic acid has a unique structure that allows it to bind with water in the skin. This helps keep it hydrated by promoting moisture and encouraging skin to hold on to more of its own natural reserves.
Skin barrier support
Skin barrier health may be a buzz phrase in beauty right now, but it’s essential if you want a healthy, hydrated complexion. A key component in this, lactic acid encourages the skin to make more ceramides, the lipids that form the glue between skin cells, helping to maintain the skin barrier’s integrity and reduce inflammation.
Who should use lactic acid—and who should skip it?
Lactic acid is well tolerated by almost all skin types and can help with conditions from bumpy or rough skin texture to dullness, hyperpigmentation, dryness, and fine lines. In instances of a compromised skin barrier, though, lactic acid—and other exfoliating acids in general—are best to be avoided. This would include active eczema, psoriasis flare ups, or people with hypersensitive skin.
