Raise your digital hand if you’ve ever applied a dot of toothpaste to a pimple. Hey, no judgment: When it comes to ushering out an unwelcome facial visitor, it’s hard to ignore a method that involves using something you already have in your medicine cabinet. There’s one big problem with the technique, though: It does absolutely nothing for your skin, and, in fact, could actually cause even more problems.

Some dermatologists are totally baffled by the origin of the toothpaste zit cure. “It’s unclear why or when the myth gained popularity, but it may have been born out of desperation to ‘dry out’ those oh-so-juicy—not to mention red and painful—zits,” Libby Rhee, DO, a New York City–based dermatologist, tells me. She maintains toothpaste is meant for teeth, which has very different needs than skin. “Toothpaste prevents cavities, keeps your pearly whites sparkling, and helps you maintain good oral hygiene. It was never meant to be a two-in-one teeth-cleaning and pimple-fighting miracle treatment.”

“Adding an irritant like toothpaste on the skin may give you some instantaneous gratification, but it’s more likely to lead to increased irritation or sensitivity, redness, and even contact dermatitis, all of which will aggravate rather than actually treat the acne or cyst.” —Dr. Libby Rhee, dermatologist

While there are plenty of reasons to leave toothpaste where it belongs, one of them resides in the ingredients list: Triclosan—a controversial anti-microbial that’s widely used in popular toothpastes—has a bad rap for wreaking havoc on your gut health and has also been linked to systemic antibiotic resistance, hormonal disruption, and even carcinogenic potential, Dr. Rhee notes. So, while you’d be safest to avoid using toothpastes containing the compound completely, it’s just another reason to not make the potentially unhealthy product pull double duty.

Additionally, putting toothpaste on your blemish will likely make it worse. “With a big zit or cyst, the main issues are inflammation and oil trapping under the surface,” Dr. Rhee says. “Adding an irritant like toothpaste on the skin may give you some instantaneous gratification, but it’s more likely to lead to increased irritation or sensitivity, redness, and even contact dermatitis, all of which will aggravate rather than actually treat the acne or cyst.”

Instead of grabbing your tube of toothpaste the next time a pimple emerges, Dr. Rhee says your best bet is going for something more acne-specific like Differin 0.1% Gel or gentle formulations of salicylic acid or benzoyl peroxide. For an all-natural remedy, put an ice cube on the skin sore to reduce inflammation. But whatever you do, just be sure to save the minty-fresh goo for your teeth—not for your face.

Get excited: These foods won’t give you acne after all. Also, here are nine game-changing facial toners for acne-prone skin.