Could shampoo be a thing of the past? Millions of us spend a lot of time and money on it, but is it necessary? Shampoo sales have gone down a lot in the UK recently as more people are changing their hair-washing habits. A recent study by Nielsen, a consumer analyst company, said: "People are working from home…and fewer people are smoking, so [they] are using less shampoo less frequently than before." The ecosalon.com website said shampooing regularly may be the reason hair gets so greasy. Shampoo makes the scalp dry, so the head produces more oil, which you then shampoo again to remove. The site said: "By shampooing less often, your scalp naturally reduces its production of [oil]."

However, many people say shampoo is good for the hair. Mark Coray, a former president of the National Hairdressers' Federation in the UK, says there is no benefit to not washing your hair. He said: "Shampoo is not abrasive or harsh to the scalp….The ingredients in shampoo help the hair to look so [glossy]….The hair's oil may build up so it starts to look like it is shiny…but it will not self-clean." A hair loss clinic in London, The Belgravia Centre, said: "Rinsing your hair is not going to be very effective after certain activities that make the scalp sweaty, such as exercising or using a sauna." It added: "Rinsing will also not remove bacteria or clean the excess oil from your scalp if you have greasy hair."