Your trusty bristles could be a breeding ground of bacteria.

Before you read any further, go take a look at your hairbrush. I'll wait. Maybe it's coated in a carpet of hair, which is fine. It's only natural that your hair sheds when you brush it. But stray hair aside, how nasty does it really look? Do you feel sticky residue lingering from your styling products? Maybe some mystery gunk clinging to the bristles like barnacles? 

Even if your brush resembles roadkill, I understand why you may not want to ditch it. While hair ties are more limited with their lifespan, your hairbrush is likely the sturdiest hair tool you own. That black Conair you've been using for years could be intact and functioning equally well as the day you bought it. Not to mention, a good-quality boar bristle brush is pricey to replace. 

But while you may have put your heat styling tools away mid-pandemic, keep in mind that the one tool you're (probably) still using daily is your hairbrush. "Every time you run a brush through your hair, you're leaving oil, dead skin cells, product build-up, and bacteria inside the bristles," says Elizabeth Hickman, hairstylist and VaultBeauty expert. With each pass-through of the brush, they're also getting added back into your hair, which can make hair look greasier, weigh it down, and perpetuate common hair problems

when-to-replace-hairbrush: hairbrush with wood handle
Credit: Getty Images

Speaking of common hair problems, the problem worsens if you have scalp issues like dandruff. According to Hickman, dandruff-sufferers should be cleaning their hairbrush regularly. Otherwise, you could be exacerbating the condition by brushing old dandruff back in.

Timing-wise, hairstylists say that once a month is the bare minimum for a hairbrush deep clean, though you can certainly wash it more frequently than that. That being said, cleaning your brush regularly doesn't eliminate the need to replace it. Even if you do your due diligence by removing the carpet of hair from the bristles every now and then, you'll eventually reach a point where a scrub-down isn't enough. 

So, how often should you replace your hairbrush? If the last time you swapped your hairbrush is when you could still go to the grocery store without wearing a face mask, it's probably been too long. "Hairbrushes should be replaced sometime between six months to a year, depending on how much product you use on a daily basis," says Hickman.

"It also depends on the quality of your hairbrush and your sanitation efforts," adds Aleasha Rivers, hairstylist and Davines Educator. "Most of the time you can look for visual cues—some examples include separating bristles, melting and fraying, product build-up, and/or cracking. These are all indicators that it's time to replace your hairbrush. Based on my experience, even if you're cleaning thoroughly, this will probably occur every six to eight months."

Don't take that to mean you shouldn't be investing in a good hairbrush. While even expertly crafted tools will eventually wear out, they have a better shot at hitting the 12-month mark. A good way to extend this time range is owning at least two brushes. One should be used to comb through your hair before going to bed each night, while the other can be used for styling each morning. 

"Ultimately, a high-quality, well-cleaned brush can be really helpful to hair health," says Rivers—just don't get too attached.