Why shampoo?

Washing the hair is a lot like washing skin. Water can remove most visible dirt and debris, but might not eliminate odors or oily deposits. Shampoo helps water remove dirt, debris, and odors, such as smoke or sweat effectively.

Shampoo cleans the hair with chemicals called surfactants. These are soaps that remove surface debris from the scalp and hair. Many shampoos also contain compounds called sulfates, which produce a rich lather that removes oil from the hair. This can help the hair look cleaner, but it can also damage the hair.