Guy Smarts How often should you wash your hair?

How? Just wet your mane with plain water. (You can rock a shower cap if you want, though.)

You’re probably thinking that seems unsanitary, but according to the experts, you’re wayoff.

"Obviously every guy is different but on average I recommend washing with shampoo every three days," , a dermatologist at Manhattan Dermatology Specialists, says. In fact, washing daily can actually backfire, leaving your scalp and hair in poorer condition.

Celebrity hairstylist Ken Paves, who's worked on soccer star David Beckham's grooming line as well as with stars like Jennifer Lopez and Jessica Simpson, agrees.

"Two to three times a week is best to ‘wash’ your hair with a shampoo," Paves says. "For the days in between, I recommend rinsing the hair with water alone. For a fresh feel and smell, you can condition from the mid-shaft out."

Why shouldnt you wash your hair daily?

“Neither guys or gals need to wash daily unless their scalps are particularly greasy," Bard says. "Most people report that their hair doesn't accumulate enough sebum to feel greasy until day three."

Of course, if you do have a particularly greasy scalp, you sweat a lot, or have super thin hair, maybe washing every other day is preferable, but still don’t do it daily.

"Every other day is ok too if that's what the individual's oil production calls for,” she says.

In fact, you can actually benefit from that extra day or two.

"Sebum protects our skin from over drying, so you definitely don't want to over strip it by washing every day," Bard says. "Additionally washing the hair daily takes a toll on the hair as well, not just the scalp."

When should you wash your hair?

Don’t get carried away with skipping shampoo, though.

"Washing less than that allows for a build up of oils in the scalp, which can lead to an overgrowth of yeast that naturally lives on the skin, leading to dandruff,” Bard says.

And as if those little white flakes aren’t bad enough, it may even lead to hair loss. "It's also believed that the oils on the scalp can trap DHT the hormone responsible for male (and female) pattern hair loss thereby exacerbating it," she says.

You should rinse more than you wash.

Wetting your hair depends on how sweaty and dirty the hair feels.

If it’s been a little toasty outside, you’re probably fine to either keep it dry or rinse with plain water.

"[If not wetting it in the shower], the hair will dry, you can wash the sweat out the next day. Not a problem if it doesn't look or feel bad," Bard says. If it looks gross, feel free to rinse with water.

But if you’re coming from CrossFit and your hair is stinky and greasy, plain water probably won’t cut it. "Sweat alone can be rinsed off but often times water alone is insufficient to remove dirt and oil," she says.

And your hair type plays a role in how often you should wash.

It’s a good idea to use products and a shower protocol .

“Thinner hair is more delicate and will likely like do well over-washing [meaning taking the every other day approach] but also tends to look greasier faster. This requires a delicate balance,” Bard says.

“For these men I recommend washing every other night, as freshly washed hair that is less weighed down by grease and dirt gives the illusion of more volume,” Bard suggests.

And it probably feels a whole lot better to touch, honestly. For a thick head of hair, go for the three-day mark - you’ll be fine.