Some opinions on lactic acid.

Lactic acid, an alpha-hydroxy acid (A.H.A.), is known for its keratolytic properties. Indeed, it accelerates cell renewal by eliminating dead cells from the epidermis, thus revealing smooth, uniform, and radiant skin. However, compared to glycolic acid, which is another A.H.A., lactic acid is less irritating. This can be explained by the fact that lactic acid has a higher molecular weight (90.08 g/mol) than glycolic acid (76.05 g/mol). Therefore, it penetrates the epidermis less deeply and acts superficially. In addition, lactic acid is naturally found in the skin. It is part of the NMF that improves skin hydration. Its less irritating action is also explained by its hydrating properties.

Note : The NMF or Natural Moisturizing Factor represents 30% of the total dry weight of the stratum corneum. It is composed of amino acids, their derivatives, and extracellular compounds such as lactic acid or urea. Its hygroscopic properties allow it to capture and retain water in the stratum corneum, thus maintaining good skin hydration.

In skincare, lactic acid can be of synthetic or plant-based origin. At Typology, the lactic acid found in the gentle peeling serum and in the peeling mask is obtained by fermenting the sugar present in corn seeds using specific bacteria, such as Lactobacillus.

These individuals tested the gentle peeling serum and appreciated it for various reasons.

• Emilie G. : "I really liked this treatment. I apply it in the evening after cleaning my skin and before the botanical blend with peony. After a few days, I really saw a difference on my skin. I love it.";

• Morgane Y. : "My skin texture has improved, I have far fewer blackheads, and most importantly, no more pimples. A fantastic and easy-to-use treatment."

• Kevin D.: "I was somewhat skeptical before purchasing this treatment since I've already tried several others. To my great surprise, this Typology treatment is truly fantastic. It works very well on blemishes after several uses. However, be careful with sun exposure. You need to apply sunscreen to protect yourself because it quickly heats up the skin. I prefer to use it in the evening before bed."

• Céline C. : "The texture of my skin softened in 3 days and after 15 days, some acne scars began to fade. I'm eager to continue and see the results over a longer use."

• Charlotte S. : "I have been using this serum for a month and I notice a real improvement on my skin. I don't know if this is due to the use of this product but it's the only new addition to my routine. I feel like my blemishes are disappearing faster and my skin is more even. It doesn't have a particular smell and doesn't irritate my skin at all, which is usually sensitive and reactive."

Thus, users have noticed a change in the quality of their skin, which appears smoother, softer, and with fewer pimples and blackheads. Moreover, the serum is even suitable for people with reactive and sensitive skin. However, if you notice excessive irritation, discontinue its use.

• Rotsztejn H. & al. Lactic and Lactobionic Acids as Typical Moisturizing Compounds. International Journal of Dermatology (2018)