pH stands for “potential hydrogen” and is used to describe the acid-alkaline ratio of a substance, which ranges from 0 (the most acidic) to 14 (the most alkaline).
Our skin has a special feature: its surface is slightly acidic.
The surface of the skin is composed of a hydrolipid protective layer (the acid mantle) which has an average pH value of 5.5. The acidic pH value stabilizes the skin’s function as a barrier, locks in hydration, and wards off pathogens that can cause disease.