SEBUM: EXPLAINED

Hairs have a sebaceous glands (see opposite sketch) generally located in the skin surface, with an excretory channel.

The sebum is secreted by the sebaceous glands to protect the skin with a lipidic film. It protects it from microbes while acidifying it (presence of lactic acid and fatty acids) and gives it a certain impermeability and flexibility. Moreover It resides on the hairs.

Oily hair is due to a too big quantity of sebum on the hair and the scalp. An excess of sebum brings about the acne. The reverse condition, too little sebum results in the drying-up of the skin and dry hair.