Vorlage:Mergeto

Hair washing is the cosmetic act of keeping hair clean by washing it with shampoo or other detergent products and water. Hair conditioner may also be used to improve hair's texture and manageability. Two-in-one shampoos, which have both detergent and conditioning components, are now commonly also used as a replacement for shampoo and conditioner.

To remove the grease from the hair, some people apply a surfactant, most usually shampoo, but sometimes soap to their hair and lather the surfactant with water. The surfactant is rinsed out with water along with the freed dirt and dust it bonds to.

There are also dry shampoos, which are powders which remove grease from the hair by soaking it up prior to being combed out.

As hair is self-regulating shampoos and conditioners are not needed to keep hair clean. The scalp produces an organic oil which protects the scalp from dust, dirt and bacteria and keeps the hair soft and moisturised. Shampoos, conditioners and other cosmetic products strip the majority of natural oils leaving the scalp unprotected and irritated and the hair appearing 'lifeless'.

"Left to their own devices, our own natural oils in effect wash our hair without water or extra products. In fact, hair products have been shown to over-stimulate oil glands and attract dirt." taken from "Do we need to wash our hair?" by Leo Hickman, Guardian Unlimited Money, March 3, 2005, retrieved September 26, 2006

Certain cultures dictate hair washing at various frequencies from daily to monthly.

• Yudu is a Korean festival that involves washing hair to wash away bad luck.
• Ghusl is an Islamic act that dictates how the hair should be washed.

Of course, there is no actual biological need to wash hair. However, hair-washing appears to be a near universal culturally-sanctioned hygienic practice. Contrary to popular rumour, all hairstyles can be washed; for example, Rastafarians can and do wash their dreadlocks.

• Hair care
• Personal grooming