"Last night my hairdresser dropped a bombshell about my dry shampoo habits."

Last night, my hairdresser gave me two things – an excellent (and much-needed!) haircut and colour and a major bombshell about my dry shampoo usage.

You see, I’m a slave and a lover to the dry shampoo cult.

It’s a saviour, the magic powder that means I can hide the fact I opted for a Netflix binge over washing my hair. Again. As anyone with curly hair knows, it can be the difference between washing your hair every few days or once in a week – or more. (Sorry).

If you didn't selfie your new haircut, did it really happen? Image: Brittany Stewart

But while there's no doubt dry shampoo is a useful little product, it does come with a caveat.

"Dry shampoo should be washed out of your hair every 24 hours. It's to get you through, it's not a long-term fix," Academie Salon Technical Director and Session Stylist Richi Grisillo told me.

"It's putting a powder on your hair and then if you sleep on it, it's increasing friction that's in there. Not dramatically [but] it's one of those things that where you have to be careful." (Post continues after gallery.)

He said this is particularly the case if you have prelightened or naturally dry hair as build-up or overuse will cause damage.

Overuse can actually make hair dryer and even stop the scalp's production of natural oils that keep hair healthy.

As well as having negative side effects on your hair, ultimately letting it build up in your hair for three to four is "just gross".

Listen: Can you dye your hair while pregnant? Post continues after audio.

Grisillo laid out the bottom line.

"Dry shampoo is certainly a saviour but it shouldn't be your saviour every day of the week until you wash it. It should just be that 24 hour leeway, when you're like 'Ooh, it's a bit oily'," he said.

"I get that some people get naturally oily hair and it's the only thing that gets them through a few days which I guess is fine, but as long as they're maintaining it."

Lesson learned.