ACTIVE
Lactic Acid
A gentle alpha-hydroxy acid (AHA) that exfoliates while also drawing moisture to the skin, making it one of the few actives that exfoliates and hydrates at the same time.
Source
Usually made by microbial fermentation
Used for
Smoother-looking texture, skin hydration
How it works
Lactic acid is a naturally occurring AHA, today usually made by fermenting plant sugars. Like other AHAs, it works by loosening the bonds between dead skin cells on the surface, allowing them to shed more easily and reveal smoother skin underneath.
Lactic acid has been well studied on skin, where a lactic acid cream left skin looking smoother, brighter and more even in tone than a plain base cream.
What also sets lactic acid apart is that it acts as a humectant: lactate is naturally part of skin's own moisturising factor, so alongside exfoliating, lactic acid helps bind water into the skin. This dual action is why it's generally considered gentler and more hydrating than other AHAs like glycolic acid, making it well suited to sensitive or drier skin types.
Lactic acid is generally introduced a few evenings a week before building up to more frequent use, and daily sun protection matters while using any AHA. Its gentler, more hydrating profile compared with glycolic acid makes it a sensible first exfoliating acid for sensitive or drier skin.
Lactic acid has been well studied on skin, where a lactic acid cream left skin looking smoother, brighter and more even in tone than a plain base cream.
What also sets lactic acid apart is that it acts as a humectant: lactate is naturally part of skin's own moisturising factor, so alongside exfoliating, lactic acid helps bind water into the skin. This dual action is why it's generally considered gentler and more hydrating than other AHAs like glycolic acid, making it well suited to sensitive or drier skin types.
Lactic acid is generally introduced a few evenings a week before building up to more frequent use, and daily sun protection matters while using any AHA. Its gentler, more hydrating profile compared with glycolic acid makes it a sensible first exfoliating acid for sensitive or drier skin.
-
01
Exfoliates to reveal smoother, brighter, more even-looking skin
-
02
Also acts as a humectant, helping bind water into the skin
-
03
Generally gentler than other AHAs, suited to sensitive skin
Questions
What is lactic acid?
Lactic acid is an alpha hydroxy acid, or AHA. Along with glycolic acid, it is one of the two AHAs most commonly found in cosmetic products. AHA products cause exfoliation, the shedding of the surface layer of skin, and are marketed for smoothing the look of fine lines, improving the look of skin texture and tone, and cleansing pores. (US FDA, 2022)
Is there research on lactic acid for skin?
Yes. In a study on skin, a lactic acid cream used twice a day left facial skin looking noticeably better overall than a plain base cream, and skin looked less rough and more even. (Stiller et al., 1996)
Does lactic acid help skin hold moisture?
Yes. Lactate, the salt form of lactic acid, is part of the skin's own natural moisturising factor. Levels in the skin's outer layer naturally dip from summer to winter, and they are closely linked with how hydrated and supple that layer is. (Nakagawa et al., 2004)
Where it comes from
Lactic acid is now mainly made by microbial fermentation, using strains including Lactobacillus species. (Tang et al., 2024; Rahman et al., 2025)
Good to know
Like other AHAs, lactic acid can make skin more sensitive to the sun while you are using it, so finish your morning routine with a daily SPF. As with any new exfoliating acid, patch test first if your skin is easily irritated. (US FDA, 2022)
The research
- Stiller MJ, Bartolone J, Stern R, Smith S, Kollias N, Gillies R, Drake LA. Topical 8% Glycolic Acid and 8% L-Lactic Acid Creams for the Treatment of Photodamaged Skin: A Double-Blind Vehicle-Controlled Clinical Trial. Archives of Dermatology. 1996;132(6):631-636. PMID: 8651713. (opens in a new tab)
- US Food and Drug Administration. Alpha Hydroxy Acids, 2022 (opens in a new tab)
- Nakagawa N, Sakai S, Matsumoto M, Yamada K, Nagano M, Yuki T, Sumida Y, Uchiwa H. Relationship between NMF (lactate and potassium) content and the physical properties of the stratum corneum in healthy subjects. Journal of Investigative Dermatology, 2004 (opens in a new tab)
- Tang J, Hu Z, Pu Y, Wang XC, Abomohra A. Bioprocesses for lactic acid production from organic wastes toward industrialization: a critical review. Journal of Environmental Management, 2024 (opens in a new tab)
- Rahman NA, Ngaini Z, Farooq S, Ai Ling SC, Shahren PNJ. Sustainable lactic acid production from agricultural waste: a review of current techniques, challenges and future directions. Bioresources and Bioprocessing, 2025 (opens in a new tab)
Found In
Type: Face Care
Lactic Acid Overnight Concentrate
30mlRegular price £38.00Sale price Regular price
New
Type: Face Care
Niacinamide Smoothing Eye Masks
7 pairsRegular price £28.00Sale price Regular price
