Some grooming products are just too good to be true: like that 3-in-1 shower gel, face wash and shampoo that claims to reverse ageing, hide dark spots and generally turn you from a four out of ten to a straight-up seven.

Leave-in conditioner doesn’t fall into the category of snake oil. Whether you dread the post-wash fluff, like to be in and out of the shower faster than an F1 pitstop, or just want to streamline your bathroom clutter, this is one piece of kit that genuinely could be the answer to a good handful of your grooming dilemmas.

But what exactly is it, which ones are best and how do you use them? Here, with the help of six experts behind the locks of Hollywood actors, athletes and pop icons, is everything you need to know.

What Is Leave-In Conditioner?

“Leave-in conditioner is a lighter version of a regular hair conditioner as it is free from oils,” explains Davide Barbieri, a hair stylist with a client list that includes Ansel Elgort, Anthony Joshua and Robbie Williams.

“It typically comes in spray or cream format, and it is used after shampooing on towel-dried hair. It helps hair to retain moisture all day long, keeping it soft and shiny without weighing it down. It is also a very good detangler, so if you wear your hair mid- to long-length, it will cut down time spent brushing out any knots.”

Who Does It Work For?

“Leave-in conditioner is good for all hair types as it’s lightweight, doesn’t weigh fine hair down and can simultaneously add volume to limp locks. It’s also ideal for coarse, curly or afro hair, which are prone to dryness,” adds Davide. “It’s great for those who live an active lifestyle, those who go to the gym or travel frequently, or are just generally on the go.”

How Should You Use Leave-In Conditioner?

“After shampooing, towel-dry your hair thoroughly – if hair is still too wet the product won’t be absorbed properly and won’t be as effective. Apply your leave-in conditioner to the lengths, avoiding the roots as this is where your hair is naturally oiliest. If your hair is longer, apply it to the lengths and brush it through with a wide tooth comb to the ends to help detangle. It really is a fool-proof hair product,” and one you could do with adding to your rotation.