Most of us are probably guilty of doing a quick internet search to deduce how often we should wash our hair. Some of us scrub our locks well every day, others every other day and multiple times a week.
But a new TikTok trend suggesting you don’t wash your hair for a long time is gaining traction, with one woman leaving it 17 days between washes.
The woman who uses the handle @emilyalexaander on the video sharing site posted a video explaining that she finally washed her hair on day 18.
A social media user said it “doesn’t smell bad” and it also doesn’t feel particularly greasy, which is to be expected after almost three weeks without washing.
There is also an increasing emphasis on styling unwashed curls with hashtags such as “dirty hair”, which has received 169.1 million views, while “dirty haircut” has an incredible 19.7 million views.
So is it possible to train your hair to need washing less often? “Your scalp is skin, and no skin can be trained to need less washing,” advises Anabel Kingsley, trichologist at Philip Kingsley. “Like the skin on your face or armpits, it is living tissue that sweats, produces oils, and sheds dead skin cells. Your hair, when it grows back, is dead tissue.
Which means it can’t really be taught anything. But before we lose you, it’s worth noting that while you can’t train your hair to need less washing they can learn to change the mode of washing your hair. Which can help reduce oil buildup that can make it harder to aim for fewer days of washing.
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What will happen to your hair if you wash it less often?
“At first, the hair just gets dirty and the scalp becomes oily,” explains Kingsley. “The long-term implications may be more serious. Your scalp can really suffer in terms of health if you don’t cleanse it often enough. For example, you may experience itching, flaking, excessive greasiness, and general irritation. This can have a knock-on effect on your hair as scalp health is closely related to hair growth.”
What will happen to your hair if you wash it more often?
In general, shampooing daily or every other day is ideal.
“Keeps the scalp clean and healthy, which in turn promotes hair growth,” advises Kingsley. “Frequent shampooing also removes everyday dirt and product residue from the hair.”
What is the optimal time to leave hair between washes?
While TikTok tells us it’s 17 days, according to Kingsley, we should actually wash every day or at least every other day.
“That said, if washing your hair more often means more heat styling, you may run into hair condition issues,” she explains. “It’s about finding a balance. As a general rule of thumb, don’t leave more than three days between shampooing.”
Watch: A motorcyclist washes his hair with shampoo in the rain while waiting at the traffic light
So you can’t train your hair to need washing less often?
Unfortunately not. “Your scalp is skin and needs to be cared for just like your face,” explains Kingsley.
“Shampooing daily or every other day helps keep your scalp healthy and free of flakes, sweat and excess sebum. When it comes to hair, the shampoo removes dust, dirt and old product.”
Think of hair products like makeup, Kingsley suggests.
“Don’t leave foundation or blush on your face for days – nor should you leave styling mousse or hairspray on your hair for long periods of time.”
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How can you make your hair last longer between washes?
Kingsley suggests using a soothing, astringent scalp toner after shampooing to help regulate sebum production. She recommends the Philip Kingsley Scalp Toner, which contains witch hazel to help absorb excess sebum, as well as antibacterial and anti-inflammatory ingredients.
“Once a week, apply an intensive conditioning treatment to your hair before shampooing,” she adds. “In addition to the deep conditioner, apply an exfoliating scalp mask to the scalp. Like your face, your scalp benefits from a gentle weekly exfoliation,” she continues.
Finally, Kingsley recommends using conditioner only on the mid-lengths and ends. “Applying conditioner to the roots can weigh down the hair and make it limp and flat,” she explains.
Is it true that the more you wash your hair, the more often you need it?
Not necessarily. “You just get used to your hair and scalp looking and feeling a certain way,” explains Kingsley. “Reapply the same logic to your hair/scalp as you would to your skin. Washing your face frequently doesn’t mean you’ll need to wash it more often.”
So now we’ve gotten to the bottom of the hair washing dilemma, here are some other myths about the barnet…
Myth: Cold rinsing makes hair shinier
Cold rinses may be refreshing, but they don’t make your hair shinier. “If anything, cold rinsing can be damaging to your hair because it constricts the blood vessels in your scalp that carry nutrients to each hair follicle,” explains Kingsley.
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Myth: Hair gets used to the same shampoo
You might think you have to switch brands of shampoo every now and then, but in fact, the shampoo doesn’t stop working as your hair gets used to it.
“If your shampoo is no longer producing the desired results, it’s likely that the condition and needs of your hair have changed,” explains Kingsley. “For example, you could trim, dye, loosen, straighten, or lengthen them.
“Or the season may have changed, such as being wetter, the sun is stronger, or the air is drier. Your health or hormone levels may also differ from a recent illness or menstrual cycle.”
Myth: Frequent shampooing makes hair greasier
No, that’s not true either. “You might as well say that the more you shower, the dirtier you get,” says Kingsley.
“Clean hair gets greasy faster than hair that is already greasy; similarly, clean clothes show dirt immediately, while dirty clothes have to get much dirtier before it becomes noticeable. It’s a matter of individual perception.
“Just as cleansing an oily face does not make the skin oily, shampooing does not make the scalp oily. The things that can actually increase oil production are hormones and stress.”