Everything You Need to Know About Lactic Acid

Lactic acid is a skin smoothing and moisturizing alpha hydroxy acid known for its gentle exfoliation. It is a larger molecule than glycolic acid, resulting in less skin penetration and therefore less potential irritation. Lactic acid has proven effective in the treatment of photoaging, hyperpigmentation and dark spots, dry skin, and mild breakouts. ^1,2

The pKa of lactic acid is around 3.8 which means at this pH 50% exists in the uncharged lactic acid form and 50% exists in the charged sodium lactate form. What’s wonderful about lactic acid is that both the charged and uncharged form provide amazing skin benefits. The charged sodium lactate is a humectant and part of skin’s own Natural Moisturizing Factor, which binds water in the skin for a plumping effect while the uncharged lactic acid provides exfoliation and increased cell turnover for brighter and smoother skin. Lactic acid increases stratum corneum elasticity by directly plasticizing and softening the stratum corneum for a wrinkle fighting benefit.³

Lactic acid at 5% has been shown in vivo to increase epidermal thickness, improve skin smoothness, reduce wrinkles, improve skin elasticity, and boost moisturization.⁴ Lactic acid can also increase ceramide production in the skin which decreases not only with age but also in the transition to the dry winter season.⁵ Lactic acid improves the skin’s resilience and barrier function making it especially appealing to those with sensitive skin that can benefit from acidification and exfoliation but need a more gentle approach. Lactic acid at 2% was also shown to decrease the number of comedones and inflammatory lesions in subjects with mild acne vulgaris most likely due to its combined antibacterial and keratolytic properties.⁶

Let’s talk about stereochemistry. Certain ingredients can have the same ingredient name, molecular formula, and sequence of bonded atoms but differ structurally. This is similar to having a left hand and right hand that are both anatomically the same but cannot be superimposed on one another. Some ingredients need to have a specific structure to be biologically active in the skin due to how they interact with skin receptors similar to a lock and key. Lactic acid has one chiral carbon so there are two enantiomers or possible structural isomers, L-lactic acid and D-lactic acid. L-lactic acid was proven to be significantly more effective than the D isomer both in vitro and in vivo for production of stratum corneum ceramides. L-lactic also showed superior efficacy in vivo for increasing skin barrier function and reducing transepidermal waterloss.⁷ Our Vegan Lactic Acid Emulsion 5% contains a highly pure L-lactic acid obtained from the fermentation of beet sugar with a stereochemical purity of at least 97%. Our Vegan Lactic Acid Emulsion 5% offers a multifaceted approach to radiant and luminous skin by combining 5% pure L-lactic acid with niacinamide and a stabilized vitamin C derivative. Lactic acid not only helps increase cell turnover to improve complexion, but also inhibits tyrosinase, an enzyme crucial for the production of skin melanin. A study showed that lactic acid’s effect on melanin production was not dependent on its acidic nature; therefore, one of its brightening mechanisms is not pH dependent.⁸ Combining lactic acid with niacinamide which inhibits melanosome transfer and vitamin C, a potent tyrosinase inhibitor, our emulsion targets dark spots and hyperpigmentation to achieve a glowing uniform complexion.

While niacinamide and vitamin C are known to stimulate collagen synthesis, lactic acid can act as an antioxidant to chelate heavy metals that increase collagen-degrading enzymes called matrix metalloproteinases.⁹ Together, this trio helps improve the appearance of fine lines and wrinkles.

With its antibacterial and keratolytic properties, lactic acid can reduce skin congestion and post-blemish inflammation while niacinamide can reduce sebum production to minimize future skin imperfections. Since both lactic acid and niacinamide increase ceramide production and reduce inflammation they have the ability to clear up spots without overdrying or causing redness. We also blended out Vegan Lactic Acid Emulsion 5% with skin soothing aloe for further skin comfort.

Our Vegan Lactic Acid Emulsion 5% is formulated to pH 4.0-5.0 for gentle exfoliation, low potential irritation, and superior moisturizing. Our emulsion is very hydrating and melts quickly into skin leaving a glowy finish. It provides exceptional skin brightening and radiance while being gentle enough for sensitive dry skin.