Shampoo

Shampoo is a hair care product used for cleaning the hair and scalp. Its primary function is to remove sebum, sweat, dirt, environmental pollutants, and other oily debris that gradually build up and can make the hair appear dull, greasy, and unclean.

The term "shampoo" originates from the Hindi word champo (चाँपो), itself derived from the Sanskrit word capati (चपति), meaning "to press, knead, soothe." This referred to a head massage that was often combined with hair washing in pre-modern India.

Modern shampoo formulations are complex mixtures of surfactants, conditioning agents, thickeners, preservatives, fragrances, and other additives. The core of the cleansing action comes from surfactants, which are amphiphilic molecules that lower the surface tension of water, allowing it to emulsify oils and suspend dirt particles. This emulsified dirt and oil can then be rinsed away with water.

Different shampoos are formulated to address specific hair types and concerns, such as dry hair, oily hair, damaged hair, color-treated hair, and dandruff. These formulations may include different types of surfactants, conditioning agents (like silicones, proteins, and oils), and active ingredients (like antifungal agents for dandruff control).

The frequency of shampooing varies depending on individual factors such as hair type, scalp condition, lifestyle, and personal preference. Over-shampooing can strip the hair of its natural oils, leading to dryness and damage, while infrequent shampooing can result in build-up and a greasy appearance.

While the primary purpose of shampoo is cleansing, many modern shampoos also offer secondary benefits such as conditioning, volumizing, strengthening, and color protection. The precise ingredients and their concentrations in a shampoo dictate its performance and suitability for a particular individual's hair.