There are plenty of myths doing the rounds about the answer to this conundrum! Will daily washing dry out your hair? If you leave it for ages will it clean itself?
These days, as a nation, we definitely wash our hair more than we did a generation ago. For many of us it's more likely to be a daily occurrence than a once a week event.
Latest haircare figures in the UK show sales for shampoo, conditioners and styling products up by 5% to break through the billion pound barrier. Shampoos and conditioners account for a large proportion of those sales.
But do we even need to bother? We've all heard the urban myth about the woman who hasn't shampooed her hair for years and it looks like silk.
So how often should we really wash our hair? It's not a cop-out but the correct answer is it depends on who you ask and on your own hair!
If you have fine hair it's more likely to look limp the day after a wash so you may want to wash it more frequently.
For curly and coarse hair every 3 days or so may be a better idea.
Some people find their hair is more manageable and looks better the day after they've washed it as it's too soft and floppy on the day itself.
"A good benchmark for hair washing should be twice a week or when you feel your hair needs it," says top hair consultant Scott Cornwall.
He says, "If you have very thick, long and curly hair and need to spend a considerable amount of time blow-drying or styling, a good weekly wash would suffice."
The advice is different from Marilyn Sherlock the Chairman of the Institute of Trichologists. "Wash it every day," she says. "We wash our bodies every day and clean our teeth twice a day, why should hair be any different?"
She says: "With all of the fumes from cars and pollution a daily shampoo and condition is ideal."
Hair that has been coloured or processed may need less washing as oil doesn't travel so far down the hair shaft so it tends to be more dry and need shampooing less.
Marilyn says that daily washing doesn't apply to African-Caribbean hair, "It's more porous and needs oiling so should only be washed every 2 or 3 weeks to prevent it breaking."
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