What happens if you don’t wash your hair for 56 days?

If you simply stop washing your hair, at some point it will get clean again by itself – at least, that’s what’s believed by a movement of shampoo-shunners. Time to put it to the test.

If our hair is washed two to four times a week, it won’t get smelly. It won’t bear alarming amounts of food scraps, germs or flakes. We reach for the shampoo bottle all the same. Why? Not for hygiene’s sake, but because it will be a matter of days for vividly bouncing locks of hair to change into greasy wisps.

Until over a century ago, we lived pretty much without shampoo. Hair could only be washed using soap bars. When soap was taken into mass production, it was still unappealing and inconvenient for washing hair. The soap had to be skived and dissolved in water first, and it left residue in the hair.
In 1908, The New York Times described washing hair as “rather a trying ordeal” and advised ladies to wash hair in good condition “every (…) month to six weeks”. This changed over the following twenty years. Schwarzkopf in Europe invented fluid shampoo: Procter & Gamble in the United States introduced the first shampoo containing modern synthetic soap.

And voilà: after World War II, the Western world had become massively hooked on shampoo. Unless you are a polar explorer or otherwise homeless, having airy, shiny and dry hair has become the norm. It is hard to imagine it could be any other way. Time for an experiment. 56 days without shampoo.

The evening of day 3 without shampoo. I comb my hair back and it stays upright. I hang my head down. My hair is so greasy it beats gravity. 53 more days to go.

There is a movement of shampoo-quitters, with a dubious sense for wordplay calling themselves no poo. They rely on an interesting theory: the sebaceous glands on the scalp become overactive from excessive degreasing. After going without shampoo for about six weeks, the glands grow “accustomed” to a diminished need of sebum. They are detoxified. The result: regular, clean hair, but without any shampoo involved.

Richard Glover suggests this isn’t utter nonsense. He’s been a fervent advocate for no poo for nine years already. “I’m still off shampoo”, he writes in an email, “and, if I may say so myself, my hair is fluffy like a kitten”.

In 2007, Glover managed to get over 500 ABC-City Radio listeners in Sydney to join him in refraining from washing their hair for six weeks. Rinsing with warm water only, was the assignment. Glover was proven right: 86 percent of the participants were at least as pleased with their hair as they were before.

The outcome cannot be checked, for all data from this unique survey are gone. But if it’s true, six out of seven people will be just fine without shampoo.

Day 7 without shampoo. Every day I rinse my hair in the shower. Since a couple of days, it has stopped getting greasier: apparently it’s saturated. My hair shines with greasiness. I only wear it in a ponytail with side part, hoping it will look “sleekly styled”.

The No Poo wiki-page doesn’t provide any sources for the sebaceous gland-withdrawal-theory, but something is to be said for it. Would people really have gone through life with greasy wisps until the onset of the industrial revolution? Did Botticelli’s Venus have greasy hair, or Mona Lisa? “Most monkey species have dry hair”, head of animal care at the Apenheul Zoo Jacqueline Ruijs assures me. “In some species, it will be coarse and dry, in others soft and dry.”
We, as human beings, may have simply lost part of our human physiology. Or is it about something else and were people from past centuries contented with a lifeless, greasy hairdo? There is no mention of it in the Encyclopedia of hair – A cultural history (Victoria Sherrow, 2006).

Day 18. It’s not that bad. My scalp doesn’t itch, there’s no funny smell. But I can hardly recall how blond hair once was. Since last weekend’s spa visit – chlorine baths included – it’s been a little better.

Greasy hair appears to be a static scientific white spot, while the ignorance regarding greasy hair is actually growing.
During the second half of the twentieth century, the effects of shampoo on greasy hair were researched in earnest, mainly in Germany and the United States. German dermatologist Max Gloor stated that greasy-haired men produced up to five times the amount of sebum of dry-haired people.

What remains the same for everyone though: after shampooing the hair temporarily becomes less greasy, but after three to five days all of the sebum will have returned. After that, the hair is saturated. It won’t get any greasier.

Day 36. Just one week after going to the spa, the grease was back. It takes my hairdo one and a half hour to dry after my morning shower. But it doesn’t turn into a bunch of dreadlocks.

Short-term experiments are not indicative for the question whether shampoo makes hair greasier and greasier. Back then, this theory was taken seriously though. There are regular speculations in this direction, Gloor wrote in 1982 in the monthly Dermatologische Monatsschrift in his article Über den Einfluß häufiger Haarwäschen auf die menschliche Talgdrüse (On the effects of more frequent hair-washing on the human sebaceous glands). He started an experiment as well. “The following experiment will contribute to the final solution of this question.” It didn’t. Gloor made his subjects wash their hair every ten days. This had no effect on the production of sebum, but that was to be expected. His experiment was too short.

The withdrawal-theory lasted for a little while. “It seems reasonable to speculate that shampooing has a major effect on the greasing of hair after washing”, researcher Michael Wong from hair dye producer Clairol wrote in 1997 in the handbook Hair and hair care.
Ever since, shampoo-abstinence has disappeared from the scientific world. Gloor is not even quoted in recent publications on washing hair. Professor Max Gloor is still alive and residing in Karlsruhe. “I do not wish to discuss my former profession”, he tells me on the telephone. “I am more interested in philosophy now.”

Day 56. For eight weeks, my hair remains more or less greasy. This morning I finally washed it again. I am surprised by the sensation of soft hair against cheek. Four days later, my scalp begins to itch. After that, things turn back to the way they were: my hair gets greasy just as quickly, and I wash it just as often as before.

If this eight-week experiment shows anything at all, it is that even the most familiar topics can stay under the scientific radar, and that washing your hair with nothing but water for weeks is surprisingly doable.

As for the “withdrawal theory”: my experiment ended in a draw. I could be one of the greasy-haired. Other people’s hair may actually turn soft like “a fluffy kitten” after six weeks.

There probably won’t be anyone interested in researching the matter any further. “This is a rather complex field of research”, Spanish hair expert Ramon Grimalt assured me on being asked for information on the effects of long-term shampoo-abstinence.

On that same day in the United States, the existence of gravitation waves was proven.

Translation: Welmoed Smith