A gynecologist says to stop wearing thongs, STAT, for the sake of your vagina’s health

I’m gonna be real with you: I don’t pay one ounce of attention to the underwear that I’m wearing. When I’m shuffling to get dressed in the morning, I grab whatever raggedy-ass (… literally) pair I have in my drawer. Which means the only qualification I have for my undies is that they’re clean (and that if they are ripped, hole-y, period-stained, or a thong, it doesn’t matter).

Well, according to gynecologists, there are certain underwear breeds that are best suited for the health of your vagina (and the hole-y type isn’t exactly one of them). Thongs are out: “Thongs may look and feel sexier compared to everyday underwear, but their anatomically unfriendly design makes it easier for harmful bacteria of the colon to find their way into the vagina and bladder, increasing the risk of infection,” says Sherry A. Ross, MD, an OB/GYN, women’s health expert, and author of She-ology. Materials like nylon, polyester, and spandex also aren’t so ideal, unless the crotch area has a cotton lining “which is more vagina-friendly,” she says. Those are fine for workouts though: “They’re comfortable, non-absorbent, and flexible,” says Dr. Ross. (Just remember to change out of them the second you’re done sweating it out.)

The most vagina-safe underwear of all, though? Cotton (yes, your mom was right). “Underwear for everyday use should fit the vagina comfortably and ideally be made of cotton,” she says. And you want it to cover your entire nether-region. “Comfortably fitting cotton underwear that properly covers your female anatomy well, including the vagina and the rectum, tends to be the best bet for the vagina in the long run. Finding the most comfortable underwear should be every woman’s mission and priority for vaginal health and wellness.”

And, guess what? If you’re a fan of going bare, Dr. Ross isn’t so anti the practice. “To each their own when it comes to wearing underwear or not,” she says. “When you don’t wear underwear the vagina and buttocks are completely unrestricted and free. The unrestricted vagina doesn’t have any underwear or panty lines or fabric to add discomfort to this sensitive area. And in addition to comfort, there’s no buildup of heat and moisture which can increase the risk of a vaginal infection.” Who knew? Going commando is OB/GYN-approved. So for the sake of your vag, go with cotton or bare (or bust).

In case you were wondering, here’s what a vagina facial is like. And this is everything that gynecologists what you to know about your vagina’s pH levels.