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No poo


"No poo" (or no shampoo) is a collective term for methods of washing hair without commercial shampoo.

There is, in normal circumstances, no medical reason for humans to wash their hair, and washing practices are determined by cultural norms and individual preferences, with some people washing daily, some fortnightly, and some not at all. From a clinical point of view, 'the main purpose for a shampoo is to cleanse the scalp', though 'most patients would disagree[,] stating that the purpose of shampoo is to beautify the hair'.

The first synthetic shampoos were introduced in the 1930s, with daily shampooing becoming the norm in the US by the 1970s and 1980s. Proponents of "no poo" practices believe that shampoo removes the natural oils (sebum) produced by the scalp—causing the scalp to produce more oil to compensate. They also believe that regular shampooing causes a "vicious cycle" to develop as it becomes necessary to shampoo regularly to compensate for the excess oils produced by the scalp (which are produced in response to being stripped from the scalp by the previous shampooing).

According to some dermatologists, a gradual reduction in shampoo use will cause the sebaceous glands to produce at a slower rate, resulting in less oil on the scalp and hair. In the 2010 book Packing for Mars, Soviet research is quoted as "the skin halts its production of sebum—after five to seven days of not bathing...." The time taken to break the cycle after adopting "no poo"-practices varies, however a "two- to six-week period" is typical.

People adopt "No poo" practices for many reasons, but one reason is concern about the effect of ingredients typically found in commercial hair care products. Shampoo typically contains chemical additives such as sodium lauryl sulfate and sodium laureth sulfate. There are health concerns about these chemicals, which can irritate the skin of sensitive people (or of anyone if not thoroughly rinsed) and are linked to higher rates of cancer. Such chemical additives are also believed by some consumers to dry out their hair. The Environmental Working Group, based in Washington, DC, compared the ingredients in 42,000 personal care products against 50 toxicity and regulatory databases and found that most shampoos have at least one chemical that raises concern (although the hair care industry counters by claiming that the chemicals are safe in the concentrations used). The group flagged the following groups of ingredients as hazardous: fragrances (the ingredients forming the fragrances are not disclosed), parabens (linked to endocrine disruption and neurotoxicity concerns), DMDM hydantoin (allergy concerns), 1,4-dioxane (which The Environmental Protection Agency has labelled as a probable human carcinogen).


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