It may seem unbelievable, but a mere century ago, it was not uncommon to go weeks—even more than a month—without a shampoo session. Nowadays, most people wash their hair at least once a day; an extra sweaty workout can even mean washing twice in a day. So, how did we go from such infrequent washing to this? How often should you wash your hair?
Without getting too distracted discussing the efficacy of modern marketing techniques for shampoo and conditioner companies, advertising was one of the driving forces behind our increase in hair-washing frequency.
At the turn of the 20th century, getting your hair “done” by a professional was the norm. Hairstyles were worn short for women back then, so they would get a wash, a cut, and a style every few weeks.
Once shampoos and conditioners (and 2-in-1 products) became cheaper than a trip to the salon, and were advertised frequently on television, radio, and national magazines, home hair care became the norm. By the 1960s and ‘70s, hairstyles were less complicated—letting it grow out and long was in vogue, removing the need for frequent salon visits.
Soon, washing hair everyday became as commonplace as brushing teeth. The products were cheap and selections abundant, so who wouldn’t want to use them?
And we did use them—lots and lots of organic hair care products. The global shampoo (and conditioner) market is expected to reach more than $25 billion by 2019.
But is it necessary?
While a lot has changed since the early 1900s, many of us may still be over-washing our hair.
WebMD says the answer is complicated. Depending on your hair type and scalp condition, you may need to wash daily. But shampoos are designed to trap oil, which we actually need for a healthy hair and scalp. Shampoos wash away sebum, which is produced by the hair and scalp, in order to keep hair healthy. The more you get rid of the sebum, the more it may actually lead to dry and damaged hair.
“[The oils] provide moisturizing and a protection barrier for the skin and hair,” Carolyn Goh, MD, assistant clinical professor of medicine at the David Geffen School of Medicine at UCLA told WebMD.
But there’s also the issue of dead skin cells and hair.
“Shedding that dead hair can stimulate new growth,” Dr. George Cotsarelis, director of the Hair and Scalp Clinic at the University of Pennsylvania’s Perelman School of Medicine told Time. “So for a lot of different reasons, I’m not a fan of going a long time between washes.”
And consider too that if you’ve been washing your hair every day since childhood, your scalp and hair have become conditioned to that frequency, and there’s a chance of over-producing sebum if you start to go longer periods between washing. It can balance out over time, but you may have greasy hair and an itchy scalp if you suddenly drop your washing.
The best bet?
Find a happy medium. Conserving water (and shampoo!) is certainly a worthy reason for decreasing shampooing frequency, and it may be healthy for your scalp to have a break, even if it’s just an extra day or two between washings.
Also, be sure you pay attention to the types of hair care products you’re using. Some synthetic ingredients can be drying and irritating to the scalp. Choose natural and organic shampoos and conditioners rich in plant oils and botanical ingredients that promote healthy hair.