Choosing underwear made of breathable, natural materials like cotton can support your vaginal health, as can other practices like proper cleaning and knowing when to replace your panties.

Your pantie guidebook to cleaning, wearing, and living.

Did you know that certain fabrics are healthier for you, that at certain times, going commando is better, or that underwear (sort of) has an expiration date?

These unspoken underwear rules can affect your vaginal health.

So we did a lot of research, dug through several underwear hygiene studies, and talked to an OB-GYN to collect eight underwear rules to live by.

You may have heard this before, but with all the cute styles in a variety of fabrics out there, it’s worth saying again: cotton is the best underwear fabric.

“The vulva is a very sensitive and delicate area, similar to the lips on your face. You want to treat [it] gently,” explains Dr. Alyse Kelly-Jones, board certified OB-GYN.

And the most simple, gentle fabric to touch your skin? Cotton. It’s also breathable and absorbent, which can help prevent yeast infections.

“Since it is healthy to have a vaginal discharge, similar to the moisture you always have in your mouth, you want your underwear to gently absorb any extra moisture,” explains Kelly-Jones.

Cotton vs. nylon vs. spandex

Synthetic materials like nylon and spandex don’t allow the area to breathe. Instead, they trap heat and moisture, creating a perfect breeding ground for yeast infections.

Natural, breathable fabrics, specifically cotton underwear, are best to support your vaginal health. They may help reduce odor and the risk of yeast infections.

People typically wear one pair of underwear a day and then put it in the laundry to be washed. However, you could wear more than one pair per day if it makes you more comfortable.

You may get away with wearing underwear two days in a row if there’s not much discharge or sweat, but studies suggestTrusted Source that most underwear contains a small amount of fecal matter, so you may want to change them daily.

If you start to feel uncomfortable because of vaginal discharge buildup, you can change them more than once a day, as Kelly-Jones reminds her patients.

“Many of my patients are bothered by this moisture and wear pantie liners all of the time,” she says. “I think this is not the healthiest of behavior, as liners can cause chafing and irritation. Cotton-lined underwear will solve this problem, and it’s OK to change more than once a day.”

After they’ve been worn, toss them in the hamper to wash. Unlike jeans, underwear shouldn’t be re-worn just to save on doing a load.

There’s a lot of debate about whether or not going underwear-free to bed is better for you.

For those who have a healthy vagina, either choice is fine. For those who deal with regular yeast infections, going pantie-free to bed may make a difference.

Going without a cloth barrier allows the area to breathe overnight and keeps moisture from building up or creating an environment for bacteria to build.

“I believe the vulva area should be exposed to the air, just like any other area of your body,” says Kelly-Jones.

If you really don’t like the feeling of being naked, Kelly-Jones recommends wearing loose-fitting pajama bottoms. Just remember, if you’re going without underwear but are wearing another type of bottom, they need to be washed frequently as well.

Basically, it doesn’t hurt to go without underwear overnight.

Whether to go pantie-free or not when working out is a personal preference. If you’re wearing shorts that have moisture-wicking underwear built into them, you can forgo the underwear.

Wearing something between you and the fabric may be more comfortable and a healthier way to catch sweat. Typically, this would be a high tech polyester that’s light and slick.

If you do choose to wear a pair, Kelly-Jones notes, “The most important thing is to make sure it fits well and doesn’t cause chafing.”

Once you find your ideal size and style, you can pick from workout-specific underwear options.

It’s always been assumed that thongs can’t be good for the health of your nether regions.

However, studies haven’t found evidence that thongs cause yeast vaginitis (YV), bacterial vaginosis (BV), or urinary tract infections (UTIs), three of the main issues people with vaginas experience. A 2019 studyTrusted Source looked at the association of thongs with UTIs, BVs, and YVs and found no evidence supporting the assumption that thongs can cause these issues.

A small, older 2005 studyTrusted Source looked directly at string underwear and found that the microenvironment of the vulvar skin didn’t change at all due to the style of underwear. The underwear had no effect on the pH, skin microclimate, or aerobic microflora. Instead, they suggested hygiene choices had a bigger impact on causing these conditions.

Douching can increase the risk of infections. A 2022 review suggests douching and washing the vulva with soap or shampoo alters the naturally occurring bacteria and increases the risk of BV.

So feel free to wear a thong when the occasion calls for it. If it feels uncomfortable or your experiencing symptoms of the above conditions, try opting for breathable cotton underwear.

All types of underwear should be handled more gently than the rest of your wardrobe, not just your special lacy, stringy thongs. This isn’t because they’re your “delicates.”

It’s mostly because they sit up against your more sensitive skin for long periods. Kelly-Jones recommends using gentle, hypoallergenic soap to wash them because “anything soapy or chemical next to the vulva can lead to irritation, itching, and allergic reactions.”

The cleanest way to wash your underwear

  • After washing, tumble dry on low heat for 30 minutes.
  • Sick roommate or family? Don’t mix your underwear in the same load.
  • If you have BV, don’t mix dirty underwear with clean underwear or with pants.
  • Wash underwear separately from clothes if they have been exposed to bodily fluids.

Pro tip: Concerned about the washing machine? Do a hot water and bleach cleanse (about 1/2 cup of bleach to a full wash-spin-drain setting) to sanitize the machine before putting your laundry in.

It sounds excessive, especially for something that gets washed so regularly. But underwear can containTrusted Source viruses and bacteria that your laundry routine may not be removing, particularly if your underwear is washed in cold water and hung to dry.

Beyond bacteria, there’s a chance your underwear could contain feces. The average pair of adult underwear contains a tenth of a gram of fecal matter.

However, throwing out your underwear every year isn’t an eco-friendly option. So, if you don’t have bacterial problems down there, you may not have to clean out your drawers annually.

But if you do experience BV or other symptoms frequently, you may want to replace your underwear every year.

The best way to wash your underwear

Here are some washing recommendations:

  • After washing, tumble dry on low heat for 30 minutes: One doctor told the New York Times that tumble drying for 30 minutes or ironing after washing can help minimize new bacteria that’s been picked up during the wash.
  • Sick roommate or family? Don’t mix your underwear in the same load: This can help avoid spreading bacteria and viruses to other clothes. Experts also recommend washing in warm water and washing these items sooner rather than letting them sit in the hamper.
  • Don’t mix affected underwear with other pairs or pants if you have BV: This is especially important for people who do laundry less frequently. Do a separate wash to keep the bacteria levels lower and avoid
    cross-contamination.
  • Wash underwear separately from clothes with other bodily fluids: In hospitals, wash clothes that have been cross-contaminated (with vomit, blood, urine, etc.) separately. Do the same with your underwear. If there are other fluids, focus on getting the blood or vomit out of the clothes and keeping them away from garments that you wear up against your private parts. For example, if you have a family member who works in a setting where they may have bodily fluids on their clothes, such as a hospital, consider washing the clothes they wear for work separately.

Even though it goes unseen (for the most part), underwear can actually play a major part in how you feel.

Research from 2020Trusted Source suggests that underwear can affect your mood, help you feel more confident, and increase your sexual desire.

Your moods may be likewise affected by “unattractive” or ill-fitting underwear.

Don’t underestimate the power of your most intimate garment or think that just because nobody sees it, it doesn’t affect how you feel.

If you’re ever feeling a little down, turn to your sexiest pair of panties. Like a power pose, it may give you a nice confidence boost.

What underwear do gynecologists recommend?

Gynecologists typically recommend you wear underwear made from natural fabrics, like cotton. Cotton underwear may helpTrusted Source lower the risk of certain infections.

What underwear should you wear to avoid yeast infections?

Cotton underwear can help absorb moisture and prevent yeast infections.

What is the best material for underwear to prevent odor?

Wearing cotton underwear can support your vaginal health and prevent moisture that may lead to odors.

Wearing underwear made from natural fabrics, such as cotton, may help reduce moisture and prevent infections.

Other practices, such as changing underwear daily and drying your underwear at low heat, may also help reduce bacteria, viruses, and yeast that can lead to infection.

Emily Rekstis is a New York City-based beauty and lifestyle writer who writes for many publications, including Greatist, Racked, and Self. If she’s not writing at her computer, you can probably find her watching a mob movie, eating a burger, or reading an NYC history book. See more of her work on her website or follow her on Twitter.