How often do you wash your hair?
Well, according to one hair expert, probably too often.
Alexa Serowik went viral on TikTok after uploading a video explaining how often people should be washing their locks.
She advised against washing it every day, and explained that you should be trying to wash it only two days a week.
While one rule doesn't fit all - lots of us have different types of hair after all - many of us could be washing it too much.
In her video, which has been viewed more than 900,000 times, she said shampooing your hair every day could be doing more harm than good.
This is because the shampoo can strip your scalp of all its natural oils and result in dry, brittle hair.
In the comments, she explained: "You have to start training your hair.
"Really important for hair growth - your hair will adjust to less washing and produce less grease."
She added: "When you start taking proper care of your your hair, it will not get as greasy, it will adjust, I promise!"
This theory about shampoo has been backed up by other hair experts - including hair stylist Julien Farel.
In his experience, only those with an oily scalp will need to wash every day.
This occurs when sebaceous glands in the skin tissue on the head produce too much sebum (natural oil).
But for most people - Julien says any surplus sebum can be removed with a shampoo-free wash, meaning only excess oil is stripped from the scalp.
People were left divided by the TikTok video - with some saying their hair needed washing every day.
One person commented: "I have to wash my hair every day, it gets too oily."
But another said: "I used to wash mine every day and now I wash it twice a week."
Another said: "Some people need to wash it every day while others can do it once or twice a week.
"It really depends on the hair and scalp texture - there's no right or wrong answer."
