It is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in bar form, like a bar of soap.
It is used by applying it to wet hair, massaging the product into the hair, and then rinsing it out. Some users may follow a shampooing with the use of hair conditioner.
The goal of using shampoo is to remove the unwanted build-up in the hair without stripping out so much sebum as to make hair unmanageable.
Shampoo is generally made by combining a surfactant, most often sodium lauryl sulfate or sodium laureth sulfate, with a co-surfactant, most often cocamidopropyl betaine in water.
Specialty shampoos are available for people with dandruff, color-treated hair, gluten or wheat allergies, an interest in using an “all-natural”, “organic”, “botanical” or “plant-derived” product, and infants and young children (“baby shampoo” is less irritating).
There are also shampoos intended for animals that may contain insecticides or other medications to treat skin conditions or parasite infestations such as fleas.
It is generally made by combining a surfactant, most often sodium lauryl sulfate or sodium laureth sulfate, with a co-surfactant, most often cocamidopropyl betaine in water to form a thick, viscous liquid.
Other essential ingredients include salt (sodium chloride), which is used to adjust the viscosity, a preservative and fragrance. Other ingredients are generally included in shampoo formulations to maximize the following qualities:
ease of rinsing
minimal skin and eye irritation
thick or creamy feeling
pleasant fragrance low toxicity
slight acidity (pH less than 7)
no damage to hair
repair of damage already done to hair
Many shampoos are pearlescent. This effect is achieved by addition of tiny flakes of suitable materials, e.g. glycol distearate, chemically derived from stearic acid, which may have either animal or vegetable origins.
Glycol distearate is a wax. Many shampoos also include silicone to provide conditioning benefits.