Shampoo is a hair care product, typically a viscous liquid, used for cleaning hair. It can also be found in bar form, similar to soap. To use shampoo, apply it to wet hair, massage it into the scalp, and rinse it out. Many people follow shampooing with a hair conditioner.
The primary purpose of shampoo is to remove excess sebum and dirt from the hair without making it unmanageable. Most shampoos are made by combining a surfactant—usually sodium lauryl sulfate or sodium laureth sulfate—with a co-surfactant like cocamidopropyl betaine in water. These sulfate ingredients act as powerful surfactants, effectively trapping oil and grease.
There are specialty shampoos designed for specific needs, such as dandruff control, color-treated hair, and sensitivities to gluten or wheat. “Baby shampoo,” for example, is formulated to be gentler for infants and young children.
Shampoo works to remove oils, dirt, skin cells, dandruff, and environmental pollutants from the hair and scalp. It's typically applied to wet hair, lathered, and then rinsed out. Common varieties include clarifying shampoos for buildup removal, volumizing shampoos, and those specifically designed for colored or permed hair.
In addition to surfactants, shampoos may include water, fragrance, preservatives, and other ingredients like cationic surfactants to enhance their effectiveness.
