
What is Lactic Acid?
Lactic Acid is an AHA – alpha-hydroxy acid – that is commonly found in exfoliating skincare treatments. While the most well-known sources of lactic acid are milk and other dairy products, it is also present in several fermented foods, such as sauerkraut and miso. Natural acids such as lactic acid, glycolic acid, and kojic acid have become increasingly popular as they offer a safe alternative to harsh scrubs and synthetic facial peels that can not only irritate the skin but even cause pain in some cases. Although you may think AHAs are a relatively new addition to the world of skincare, milk, and hence lactic acid, has been used for centuries as an effective skin soother and milk baths are still recommended as a way to alleviate dryness, sunburn, and rashes.

What are the main benefits of Lactic Acid?
As with all AHAs, lactic acid is an excellent exfoliating ingredient, helping to detach dead cells from the skin surface so they can be easily washed away. This action not only gives the complexion a brighter, more revitalized appearance as fresh new skin cells are revealed but also encourages cell turnover, improving the long-term health of the skin. However, it has other benefits that go beyond mere exfoliation! Used regularly, lactic acid is known to reduce hyperpigmentation such as age spots and other discoloration, enhance the synthesis of collagen for firmer skin that’s more resilient against damage, and minimize pore size, giving the complexion a clarified, more even texture. Most skincare experts would agree though, that of all the natural acids, lactic acid comes out on top for helping prevent moisture loss by increasing the production of ceramides, the lipids that form the skin’s vital natural barrier.
Who should, or shouldn’t, use Lactic Acid?
Lactic acid has a larger molecule size than other AHAs so while that means it doesn’t penetrate the surface as well as glycolic acid, for example, it also gives it a gentler action that makes it suitable for most people, even those with sensitive skin. Thanks to its superior moisture-retention properties, lactic acid is ideal for people with dry and mature skin types, reducing flaky, rough areas for a smoother, softer texture, but can also benefit individuals with oily skin by reducing the pore-clogging grease that can lead to blemishes. It should be noted though, there is always a chance of irritation when using any form of AHA – if you have concerns, consult with a dermatologist and always perform a skin patch test first. Anyone suffering from rosacea, eczema, or psoriasis should never apply AHA to their skin.
What type of Lactic Acid product is best?
If you’ve decided that you’d like to try using lactic acid as part of your skincare routine, there are many products available that contain this gentle AHA, either on its own or blended with other fruit acids. It’s important to be aware that it does come in different strengths – if you’ve never used lactic acid before it’s best to start with a low concentration of about 5%, moving up to 10-15% as your skin becomes more tolerant. Products that are designed to be used daily, such as facial washes, toners, and moisturizers are generally milder, so while they’re ideal for new users or those with a low tolerance level, effects on your skin will be much more gradual. To get optimal benefits from lactic acid, experts recommend using a serum, which you’ll often also see referred to as a peel. With a higher concentration of acid, these treatments should be used a couple of times a week, rather than daily, but they start working quickly, often showing visible results within just a few applications. Just remember to always apply a sunscreen if you’re using any kind of AHA as they do increase your skin’s sensitivity to the sun.
Ready to see lactic acid in action? Check out this list of the top-rated serums picked by our skincare experts!