Washing Your Hair Once a Week May Not Be a Good Idea—Even If It Looks Clean

Spoiler alert: washing your hair once a week may not be a good idea. And yes, even when it feels clean.

The debate around how regularly you should wash your hair is a heated one, but we’re hoping to settle it finally. While some experts say that washing your hair once a week is fine as long as you use a good shampoo and your hair responds well to that frequency, there’s another side to the argument. If your hair is extremely dry and not washed often enough, it can lose its natural moisture with age. According to stylist Rosi Fernandez, director of Ananda Ferdi it is not advisable to go for more than a week without washing hair, as “follicles become clogged and do not get oxygenated,” she explains.

When it looks clean, but it’s not

As someone who washes my hair every day, I’ve always been a bit envious of people who can go for several days without. For example, the Kardashians’ stylist, Jen Atkin, said in an interview with Allure that she could go up to four or five days without washing, and that it was only on the last day she would resort to an updo with a sharp center parting as that’s when it started to get dirty. But the reality is that although the hair may appear to be clean, pollution (one of the major aggressors of hair in 2023) has dirtied it without you realizing. “It may look like the hair is clean but with pollution, sweat, tobacco smoke… the hair becomes saturated,” explains Fernandez.

The consequences of pollution (and not enough washing)

According to Fernandez, when hair is washed less than twice a week, the follicles become clogged and this can cause a range of problems: scalp flaking, itching, sensitivity, dandruff, and even hair loss. These small particles, which are invisible to the eye, prevent the hair from oxygenating well, which is why it is advisable to wash it more often—even with thick, dry hair that you might not feel the need to wash so frequently. The effects that pollution has on hair were studied all the way back in 1994, by the Industrial Toxicology Research Centre in Lucknow. “At that time, it was shown that suspended particles, smoke, and pollutant gases were deposited on the hair and scalp, causing inflammatory and irritative reactions that can even lead to hair loss,” explains Adolfo Remartínez, founder of Nuggela & Sulé.

Washing it twice a week

There is no universal rule for the frequency of washing hair because, as Fernandez points out, you also have to take into account the place where you live or the lifestyle you lead. “It is not the same living in a city with a lot of pollution as living in the countryside,” she says. “The climate, riding a motorcycle or a car, playing sports, the quality of the water used for washing, et cetera, also play a role.” However, even when hair is dry and thick, experts advise washing at least twice a week to remove all the residues that can accumulate on the scalp, and that saturate and weaken the hair. Fernandez also recalls the importance of emulsifying shampoo in your hands before applying it, especially if it’s an organic product. “A good rinse gives hair its shine,” she concludes.