It has moisturizing properties and promotes the penetration of active ingredients in cosmetics into the skin, making it a penetration promoting agent.

Propylene glycol is a transparent, colorless, and viscous chemical reagent that is harmless to skin tissue. Propylene glycol is added to many cosmetics, such as makeup removers that are often used. Its function is to assist water molecules in dissolving facial dirt and avoiding rapid drying of the skin during makeup removal.

In addition, propylene glycol is often added to make-up water and essence liquid, which not only has the moisturizing effect, but also helps the active ingredients of cosmetics penetrate into the skin. Of course, propylene glycol also has certain side effects, especially for people with sensitive skin. After using cosmetics containing propylene glycol, they may experience a burning and itching sensation on the face, which is caused by the irritation of the skin caused by propylene glycol. If such symptoms occur, skincare products should be discontinued.