Chances are that answer is simply – yes.
Instead of the traditional shampoo-and-conditioner routine, many experts say we should be co-washing more — short for conditioner-only washing — embracing a little grease and letting our hair’s natural oils do their job.
“Your hair needs to produce natural oils,” said Juliette Dallas-Feeney, senior social media manager and beauty influencer at Birchbox, the online beauty subscription service. “If you wash it too much, you can strip your hair of them. And if you don’t wash your hair enough, it can do the same thing because of product buildup. Your scalp can get yucky and gross.”
Experts say there's no single answer to how often people should shampoo. You may not need to do it as often as you think. It usually comes down to personal preference. For guidance, take a look at your hair type and styling choices.
“I have always said, ‘It’s fine to go a few days without shampooing,’” says Alli Webb, professional hair stylist and founder of Drybar. “For hair that’s normal in terms of oiliness and medium weight, I sometimes tell my clients to go as long as they can without shampooing.”
To get a better understanding, let’s go back to the basics. What does shampoo do?
Shampoo traps oils, so if you do it too frequently, you may dry your hair out, leaving it prone to breakage, says Angela Lamb, MD, an assistant professor of dermatology at the Icahn School of Medicine at Mount Sinai in New York City.
“Hair produces natural oil called sebum, and shampoo is an emulsifier that captures and traps excess oil, dirt, and product residue, which you then rinse out to clean the hair,” Lamb says.
For the most part, some dirt is OK and natural -- and you definitely want some oils to remain in your hair.
“They provide moisturizing and a protection barrier for the skin and hair,” says Carolyn Goh, MD, assistant clinical professor of medicine at the David Geffen School of Medicine at UCLA.
Most all experts agree the number of people who should shampoo daily is very small. Those who should are people with very fine hair, those who exercise a lot, or someone living in a very humid environment.
Rule of thumb: the thicker your hair, the less you need to shampoo.
Jeff Chastain, a hairstylist in New York City, recommends that women get their shampooing down to once or twice a week. Less washing, he said, means stronger and longer hair.
“I tell people with curly hair to use conditioner only, give it a good scrub on the head and then pull the conditioner through to the ends and rinse it out,” Mr. Chastain said.