Dentists say this common ingredient could be messing with your mouth

The best part of brushing and swishing your teeth (aside from the whole “no gum disease or cavities” thing) is that “ahh”-inducing feeling you get right after you’ve finished. And, thanks to flavoring with essential oils, these days natural toothpaste and mouthwash can give your mouth the same minty-freshness as the old-fashioned stuff most of us grew up on. But no matter how much you love that cool and tingly breath after a particularly satisfying brush sesh, there can be too much of a good thing when it comes to putting those sweet-yet-spicy smelling essential oils in your mouth.

“Using essential oils in the mouth sounds like a great, natural idea, but this should be done on occasion—not everyday,” says Dr. Mark Burhenne, creator and author of AsktheDentist.com. “The powerfully antibacterial nature of essential oils means regular use can actually upset your oral microbiome over time by killing off the good bacteria your mouth needs to fight cavities and gum disease.” As in—yes, your mouth has a microbiome.

In some studies, essential oils have been proven to be just as effective as chlorhexidine–AKA the main ingredient in prescription-strength mouthwash. But, while we’re all for going the au natural route with your oral care, in this case, it may not be the best idea. “[It] might sound like a good thing, but [essential oils are] not beneficial for long-term oral health,” says Dr. Burhenne. “If you’re using mouthwash, chances are you’re trying to make it a daily habit. But killing all the bacteria in your mouth should be something you avoid on the whole.”

“Killing all the bacteria in your mouth should be something you avoid on the whole.” —Dr. Mark Burhenne

Think about using these heavy-duty oils the same way you’d use an antibiotic. “On occasion, you need a bacterial ‘clean slate’ to get infection under control. But if you were to use antibiotics every day of your life, you’d limit your immune system’s ability to fight off any infection or disease,” he explains. “Since your oral microbiome is the mouth’s immune system, keeping it free of bacteria isn’t actually a good thing.”

In lieu of swishing with essential oils or alcohol for the sake of fresh breath, Dr. Burhenne suggests making a mouthwash of your own by mixing turmeric, L-arginine, calcium carbonate, whole cloves, baking soda, xylitol, blue-green algae, and anise. It’s essential oil, alcohol, and fluoride-free, but will still give your mouth the full cleanse it needs.

If you’re going to use essential oils in toothpaste, just know that a little bit goes a long way. “When I’m trying a toothpaste that uses essential oils, the best gauge I’ve found is to pay attention to how strong the scent of the oils is,” says Dr. Burhenne. “A light scent of peppermint is probably a sign your toothpaste has just a minuscule amount of oils in it, whereas a very strong scent might mean you’ve got too much bacteria-killing oils for daily use.” Noted—so, as with in your skin care, just keep that EO use light.

Another thing worth thinking about with picking out a toothpaste? Your gum health. And while we’re on the subject of what’s going on inside your mouth, read all about one writer’s experience with a chemical-free “mouth facial.”