What is the difference between a chemical peel and mechanical exfoliation?

The difference between the two lies in the method of action for the detachment of dead cells on the skin's surface.

Generally, a chemical peel involves substances known as AHA (alpha hydroxy acid) and BHA (beta hydroxy acid). These molecules eliminate keratinocytes by breaking the ionic bonds, thereby destabilizing the stratum corneum and causing its gradual detachment. The most common AHAs are glycolic acid and lactic acid. Glycolic acid, being smaller in size than lactic acid, penetrates deeper into the epidermis, hence its greater potential for irritation. For this reason, chemical peels based on lactic acid are recommended for the most sensitive skin types. The most common BHA in cosmetics is salicylic acid. Its antibacterial properties make it an active ingredient of choice for the chemical exfoliation of combination to oily skin with imperfections.

Mechanical exfoliation detaches dead cells from the epidermis through friction. There is no "chemical" action on the surface of the epidermis. Depending on the size of the solid particles present in the product for abrasion, mechanical scrubbing can be more or less aggressive to the skin. Micro-grains such as powders derived from fruit kernels are often favored for exfoliating the face and chest. Larger grains, on the other hand, allow for exfoliating parts of the body where the skin is thicker and less sensitive, like the feet or legs.

Take note : for the face, it is recommended to perform a chemical or mechanical exfoliation once or twice a week, to restore radiance to the complexion, promote cell renewal, and smooth the skin.