Hair washing is little bit like Marmite - everyone's got a very strong opinion on how often hair should be washed, and it's nigh on impossible to get someone to shift their beliefs.
While there are legions of women who swear by their daily rinse and repeat, plenty of others find their hair in better nick when they cut down on washing it - or instead, go for a 'co-wash', and wash their hair just with conditioner. A recent study by Remington revealed that while one in five women wash their hair every day, two thirds consider hair washing a chore, with over half wishing they could cut their washing routine down to twice a week or less.
One thing's for certain: the A-List seem to be big fans of the infrequent wash.
Amanda Seyfreid revealed that she only lathers up once a week, relying on dry shampoo the rest of the time. Amanda's not alone: plenty of stars swear by infrequent washing to preserve their hair's natural oils - and give their blow-dry that lived-in texture. We've compiled a quick crib sheet for you on the A-list's washing habits...
Kim Kardashian - Every 5 days. Kim's been pretty vocal about having a blow-dry every 5 days, then letting it drop out and get more ruffled as the week goes on.
Jennifer Aniston - America's favourite head of hair didn't wash her hair for two days prior to the Golden Globes, her stylist told us.
Lorde - Apparently she keeps her bouncy, curly mane in check with a wash every one to two weeks.
Ciara - Said she can go 'a good two weeks' without lathering up. We have to say it looks good on her.
Shailene Woodley - The actress who loves oil pulling and other slightly bizarre beauty practices (some involving eating clay - do not try at home) takes the crown with a once a month hair wash, saying 'the oilier the better'.
As for the expert line, we asked some of our mane men what they thought. Marc Trinder, Creative Director of Charles Worthington, told us "In general, many people wash their hair too much. Natural oils are essential for nourishing and conditioning the scalp and hair, so if your excessively washing these away it can cause more problems long term. Every 2-3 days is okay."
Cheryl Munoz from Daniel Galvin recommended: "Not too dry or oily hair, twice a week. Oily hair should be about 3-4 times a week. Dry hair once a week."
Jordan Garrett, of Hershesons, advised, "I would personally recommend washing no more than three times a week. The front section of the hair gets oilier faster, as it is the hair that women play with unconsciously, but you can refresh this with a burst of dry shampoo rather than a full hair wash. This will preserve your hair colour, and the natural oils protecting your hair and scalp."
Amy Heath, from FOUR London, told us, "The ideal shampoo process for hair that's not super oily is twice a week. For people who can't go without washing their hair everyday, I would recommend giving it just one shampoo and condition."
When it comes to Grazia beauty team, we range from once a day (sans brushing) to a Kim-style five-day stretch. Hey, each to their own...