The list of lactic acid’s benefits is lengthy. But does it include skin lightening too? Continue reading to find out whether or not lactic acid lightens the skin and fades discolorations. We’ll keep this short and sweet!
What is lactic acid?
Lactic acid is the mildest alpha-hydroxy acid (AHA), mainly derived from milk or fruit sugars. Its large molecule doesn’t let it penetrate the skin’s surface, making it a light keratolytic — aka a peeling agent. Aside from exfoliating, lactic acid is a humectant that pulls water into the skin to hydrate it, making it arguably one of the most important ingredients in skincare.
How does lactic acid lighten the skin?
Since it’s an exfoliant, lactic acid lightens the skin by loosening the bonds between dead cells. This makes old, pigmented cells easier to remove from the skin’s surface, which in turn reveals a brighter complexion. Studies confirmed that thanks to its ability to encourage cell turnover, lactic acid may lighten pigmented skin, reducing the look of dark spots and evening skin tone.
Even if lactic acid is a gentle AHA, its exfoliating power is not to neglect. When used in the right concentration, lactic acid sheds dead cells and replaces them with brighter, softer skin, leading to a lightning effect.
On top of that, besides exfoliating, another lactic acid mechanism to whiten the skin is by regulating melanin production, the pigment that gives skin color. When the body produces too much melanin, the skin gets darker. Thus reducing the levels of this pigment is considered one of the most practical skin lightening procedures.
An Experimental Dermatology research concluded that lactic acid suppresses melanin formation by directly inhibiting tyrosinase activity. […] Lactic acid might work on pigmentary lesions not only by accelerating the turnover of the epidermis but also directly inhibiting melanin formation in melanocytes.
In layman’s terms, this means that lactic acid hinders the apparition of dark spots by stopping melanin production. Similarly, chemical peels with lactic acid are often used to treat melasma — a condition that causes dark patches of the skin — since it inhibits melanin.
Nevertheless, most research regarding the effects of lactic acid in skin lightening was done with high concentrations of above 70% substance, which you can’t normally use in OTC peels. So for prominent skin discolorations, at-home chemical peels won’t help you too much since they use no more than a maximum of 30% lactic acid. In this case, the only solution is to perform professional treatments.
How to lighten my skin with lactic acid?
In the case of easily reactive skin, a lighter peel with 5% lactic acid is ideal. Even if the lightning process is slower, you don’t risk irritating your skin. For all other skin types, a medium lactic acid peel will do. If you fancy fast and safe results, go for deeper peels made in-office by a professional.
To avail all lactic acid benefits in skin whitening, equally important is SPF use. Sunscreen is non-negotiable all year round, every single day. But it becomes even more of a must when you’re using lactic acid. Sloughing away dead cells, the lactic acid can make your skin more prone to sun damage, hence dark spots. Not using SPF while following a lactic acid treatment will get you the opposite effect and you risk developing even more dark spots.
So a short recap: lactic acid can lighten the skin texture by accelerating cell turnover and suppressing melanin formation. Hence, lactic acid is effective for treating skin discolorations such as hyperpigmentation, melasma, sunspots, and dark patches.
- Tang SC, Yang JH. Dual Effects of Alpha-Hydroxy Acids on the Skin. Molecules. 2018;23(4):863. Published 2018 Apr 10. doi:10.3390/molecules23040863.
- Usuki, Akiko & Ohashi, Akiko & Sato, Hirofumi & Ochiai, Yasunobu & Ichihashi, Masamitsu & Funasaka, Yoko. (2003). The inhibitory effect of glycolic and lactic acid on melanin synthesis in melanoma cells. Experimental dermatology. 12 Suppl 2. 43-50. 10.1034/j.1600-0625.12.s2.7.x.
- Usuki A, Ohashi A, Sato H, Ochiai Y, Ichihashi M, Funasaka Y. The inhibitory effect of glycolic acid and lactic acid on melanin synthesis in melanoma cells. Exp Dermatol. 2003;12 Suppl 2:43-50. doi: 10.1034/j.1600-0625.12.s2.7.x. PMID: 14756523.