Which of the following is recognized as a humectant?

A humectant is a substance that attracts moisture from the environment and helps to keep skin hydrated. Glycerin is a well-known humectant commonly used in skincare products due to its ability to draw water from the air into the skin, thereby helping to maintain moisture balance.

While propylene glycol is also a humectant and widely used in cosmetic formulations, glycerin holds a more established reputation in the industry specifically for its moisturizing properties. It's effective in binding water and preventing transepidermal water loss, which makes it highly beneficial for dry skin—important factors in CIDESCO studies. Consequently, while propylene glycol is indeed a humectant, understanding the typical characteristics and applications of glycerin adds to its recognition in this context.

Silicones and petrolatum are not classified as humectants. Silicones primarily serve to provide a protective barrier on the skin, aiding in smooth application and imparting a silky feel without necessarily attracting moisture. Petrolatum works to lock in moisture but does not attract it, so it functions more as an occlusive agent than a humectant.