The advice for unlocking glossy, healthy hair usually says to put the blowdryer down, but one hair expert has found one reason to keep on using it.
It's true that heat damage from drying, straightening or curling your tresses can change the structure of the hair. It turns out that styling with heat damages its ability to retain moisture - and also grease.
Although if you struggle with greasy hair, one TikToker has shared a piece of information that could permanently change your shower routine. Content creator Abbey Young, who is training to get her trichology certificate, came upon a surprising argument during her studies.
Taking to her TikTok account @abbeyyung, Abbey says letting your hair fully air dry can be more damaging, as reported by The Mirror.
"You will never air dry ever again after I tell you this," the trichologist in training began.
She refers to a piece of research which was published in 1981 and presented at the Annual Meeting of the American Oil Chemists' Society.
Abbey continued: "In that journal I found one of the most mind blowing sentences I've ever read about hair science. It says 'hair dried in air lost its sebum, or oil, at a slower rate than hair dried with a hot-air dryer'.
"So if you've ever wondered why your hair doesn't seem to get greasy as quickly when you blow dry it versus when you air dry it, this is exactly why."
In a follow up comment, Abbey cleared up the scientific jargon to put it simply: "Losing sebum at a slower rate = more sebum left on the scalp!"
According to Abbey, your hair will naturally lose excess oil in other ways, but blow drying your hair essentially kickstarts it.
She added that you lose 40 to 60% of the sebum a few days after from brushing your hair, sleeping on a pillow, or other ways, but using a blow dryer makes it happen faster.
It's still true that heat damage isn't good for your hair, which is why Abbey says she air dries her hair 80% of the way and blow dries the rest. She added: "You can also just blow dry your roots!"
The video has now been seen by more than 850k people, and many were blown away by finally realising why their hair gets greasy more quickly by letting it air dry.
One person said: "That makes so much sense! I've always noticed the difference but never knew why."
Another added: "So here I thought I was doing my hair a service by not blow drying it and that's what is causing my hair to be so greasy after a day!"
A third said: "That is so true! I've always wondered why I can go with more days between washes when I blow dry it! But I don't have time to do it every time."
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