Like HowStuffWorks on Facebook!

How often should you wash your hair?

        Health | Scalp Care Tips

To Shampoo or Not to Shampoo?
In the mid-20th century shampooing was a weekly endeavor left to hairdressers.
In the mid-20th century shampooing was a weekly endeavor left to hairdressers.
Stockbyte/Getty Images

So you want to maintain your status as an acceptably non-smelly member of society. Good for you. Where does this leave you? How often should you wash your hair?

It turns out the answer to that question is based on personal preference. Even among medical professionals that specialize in the skin, hair and scalp -- dermatologists and trichologists -- there's disagreement about the usefulness of shampooing and just how frequently one should use shampoo, if at all. Some advise against frequent shampooing, pointing out it leads to overproduction of sebum to compensate for its constant removal [source: Aubrey]. Others say shampooing is necessary to prevent sebum from collecting in the pores and hair follicles and leading to skin problems like acne [source: Grossman].

The concept of daily home shampooing is a relatively new one. Back in the 1950s, it was common for women to have their hair washed and styled once a week at the hairdresser. These folks got by just fine, and the trend has made a resurgence in recent years as more salons report clients that have chosen to shift shampooing to a weekly rather than daily ritual [source: Grossman].

Around the turn of the 20th century, women tended to go for about a month between salon visits. A 1908 advice column in The New York Times, however, helped usher in a sea change in shampoo usage when it told readers that shampooing every two weeks is perfectly acceptable [source: Aubrey].

Others have learned to postpone shampooing for even longer periods. An uncontrolled and impromptu study of the effects of going without shampoo was inadvertently launched in 2007 when a guest on an Australian radio show mentioned he hadn't washed his hair in a decade. After calls to the show came in, a six-week challenge was issued and 500 listeners participated. After six weeks of going without shampoo, 86 percent of the respondents reported their hair was no worse or better than it was when they used shampoo regularly [source: Lacko].

Others use different means to keep their hair clean. Dry powder products are available on the market that absorb some of the natural oils. The remnants are removed by blotting with cheesecloth and combed out [source: Grossman]. Baking soda also serves a similar purpose. Coupled with a raw egg and a final rinse with lemon juice, it provides an all-natural hair cleaning regimen [source: Siegle].