Can Thongs Cause Infections?

Dr. Jolene BrightenPublished: Last Reviewed: Sexual Health Leave a Comment

Love them or hate them, thongs are famous for keeping us comfy, making some of us feel sexy, and pantyline-free. But do thong underwear really cause infections? Thongs certainly get a bad rap on the topic of vaginal health. While some people have no problems wearing thongs regularly, others might find problems with infections, odors, or itchiness.

So which is it? Your underwear is your choice, so let’s make it an informed one! Read on to learn how thongs (and other underwear styles!) could be impacting your vaginal health, and find tips for treating yourself to the right pair of panties. 

How do Thongs Impact Your Vaginal Health?

How do thongs differ from other underwear styles? Thong underwear features a very thin strip or string of fabric between the front and back halves, which essentially sits wedged between your butt-cheeks, out of sight, but not always out of mind. Here are the most common ways that thong underwear can impact vulvar and vaginal health.

Thongs Can Cause Irritation 

Understandably, friction from the thin string on thong underwear can lead to itchiness and irritation, especially if it’s made with lacey, scratchy, or synthetic materials. A poor fitting thong can shift, finding itself on the inside of your labia majora. Ouch!

Poor fitting thongs can be especially irritating when worn for long periods of time, and friction from walking or movement can make the inflammation worse. This friction against your delicate bits can cause chafing, sores, or a “thong rash.” This is especially true for thongs that are too tight, made of irritating materials, or if you wear your thongs during exercise.

Wearing thongs can also worsen hemorrhoids. While thongs don’t cause hemorrhoids, the extra rubbing and pressure from a tight or scratchy thong can irritate existing inflammation, and make problems worse. Bottom line: they have the potential to irritate the vulva, perineum, and anus.

If your body type is such where you have a larger or more full posterior, you may experience what we call in my house the “chonie gobbling” phenomenon. This is where no matter what type of underwear you wear they are going to end up a thong anyways. Yeah, I’m outing my Latina booty right now as I tell you that we tend to wear thongs more compared to other groups. In these instances, sometimes a cotton thong that is the right size feels a whole lot better than all the material of a full back underwear gathered in between your cheeks.

Thongs Can Shift Bacteria Around 

That thong movement could, in theory, be transferring bacteria from your bum, to your vulva. Ew. Because thongs and g-strings sit right up against your anus, they’re exposed to more fecal matter than looser underwear. Bacteria like E. coli are perfectly normal in your colon, but can cause infections like Bacterial Vaginosis (BV) or Urinary Tract Infections (UTIs) if they travel to your vagina or urethra. Basically, thongs can break the cardinal rule of always wiping front-to-back to prevent contamination! 

Is this a fact that all thong underwear will do this? No, no it is not. It's going to depend on the fit, your body type, your activity, and sometimes the other clothing you wear. In short, the claim that thong underwear are a super highway for bacteria isn't totally true, but there is a potential risk in theory.

Thongs also provide less barrier between you and the outside world. Even the inside of your pants can carry bacteria from previous wears if you’ve been wearing them all week. It just depends on what you've been up to and what your laundry schedule looks like. Keep that in mind the next time you’re trying on jeans or swimsuits at a store too; it might be worth wearing full coverage underwear.

Thongs Can Alter the Balance of Your Vagina

This one is a myth: it’s not thongs themselves that are to blame here, but rather tight, synthetic and moisture-trapping fabrics. With any type of underwear, non-breathable fabrics are bad news for your business. 

The synthetic materials often used in thong underwear can trap excess moisture, creating the perfect conditions for yeast and bacteria to multiply. This can cause opportunistic organisms  to over grow, throwing off  your vaginal pH, or leading to vaginal infections like BV or a yeast infection. Signs of an infection can include itchiness, changes in discharge, or abnormal vaginal odor.

No matter the underwear style, opt for cotton, not just cotton lining of the crotch. You want material that breathes and if you're very sensitive, skip the dyes. Underwear with lace, sequence, beads, glitter, or other “fancy” materials aren't meant for all day wear. They are really designed to impress and then get left on the floor. That's the nature of this type of lingerie. Stick to cotton for your day wear endeavors.

Do Thongs Cause Infections? 

Not exactly. Although many people associate thongs with infections, there is no solid science that they are linked. 

The truth is, there are very few scientific studies on the impacts of thongs. One survey, and one earlier study actually found no link between thongs, and risk for vaginal infections. In fact, the previously mention survey recommended “that providers take a more complete sexual history to identify these risk factors rather than focusing on underwear as a primary risk factor.”

There is definitely a bias about thong underwear in the women's health world. The first time I was told to advise patients against thong underwear because “they are a super highway for bacteria” had me questioning if my instructor had any facts to base this on or if it was just a lack of cultural competency and sex positivity coming through. Take to the internet and you will find plenty of women's health providers warning you agains the dangers of thong underwear. To me, this is the wrong conversation to be having when we can instead let people have their personal preference shame free and educate about what is best practice for underwear in general.

That said, if you’re prone to infections or have not been able to clear a chronic case of yeast, it may be worth trialing briefs for awhile to see if they help. Even in when we do have more studies, I will always advise that people ask, “what is true for me” and individualize their health choices.

My advice regarding thongs is to choose the best fit and material. If you are struggling with infections, rashes, or conditions like vulvodynia or lichen sclerosis, give yourself a break from them and see if it helps symptoms. Recognize that my opinion, like anyone else advising you on thongs, is shaped by my years as a women’s health physician, anecdotal evidence, and listening to women's stories. While visible panty lines may sound like a bad time, pain, irritation, infections, and discomfort are definitely worse. 

Ultimately, your underwear choices are yours alone. If you have a rock-solid immune system, no pre-existing issues, and a resilient vaginal microbiome, you may never have to think twice about sporting a g-string. But if you are already predisposed to UTIs, yeast infections, or other problems, wearing thongs might not be for you.

How to Stay Healthy When Wearing a Thong

Before you go dumping your drawers or ditching your body-con dresses, there are some ways to keep your vagina happy while keeping your thongs. If you do plan to keep some in your wardrobe, consider these 5 tips to keep your vulva and vagina healthy while wearing a thong.

It’s all About the Material 

Because thongs are often marketed for sportswear or sexy time, they’re commonly made with stretchy spandex, shiny satins, or polyester laces. These synthetic materials can trap moisture, making prime conditions for yeast and bacteria.

With any underwear, finding soft, breathable material is key to protecting your vaginal health. Natural fibers like cotton or wool offer the best breathability, and are less irritating to the delicate skin around your vulva. Be sure to opt for underwear made entirely of natural fibers, not just the crotch liner. It’s equally important to find a thong that fits well, and isn’t too tight or rubbing uncomfortably when you move. Be mindful of dyes too as these can sometimes cause irritation.

It's also worth noting that laundry detergent can be a big time issue for dermatitis (skin inflammation). So if you're troubleshooting issues, always ask yourself, “have I recently changed laundry detergent?” While I'm cautioning, skip fabric softening, dryer sheets, and all the other endocrine disrupting chemicals to make your clothes smell like a field of flowers. A couple of drops of essential oil on wool dryer balls can actually do the trick if you really love that kind of smell, but in general, avoid the chemicals, especially on the more intimate garments.

Wear Thongs Less Often 

If you’re struggling with infections or irritation, thongs probably shouldn’t be a part of your everyday ensemble, but that doesn’t mean you have to ditch them for good. If thongs make you feel sexy and empowered, keep some around for special occasions! For days when a thong feels right, practice good hygiene, opt for breathable materials, and even consider changing into a second fresh pair during the day if you are prone to infections. Once infections are gone for good, you may be able to resume wearing thongs again. Be sure to track so you can ask what is true for your body.

Just like we all have those special underwear reserved for when you're on your period, you may want to make thong underwear a special occasion only item.

Ditch the Thong When Working Out

Hear me out for this – fancy thongs (made of lace, satin, etc) and working out really don’t mix. The good news is that these days many of the workout gear you’ll find are moisture wicking, breathable, and designed to be worn without underwear. Um, did someone just say less laundry?  

Working out often involves movement that pulls your thong back and forth, causing extra friction, irritation or chafing. Hello cycling on a bike! Fuller-coverage panties without laces or textures may let you get your steps in without risking thong-burn.

Thongs or no thongs, always make sure to shower and change into dry, breathable clothing as soon as possible after your workout, (no matter how cute those leggings would look at brunch). Remember, we’re talking about people prone to UTIs, yeast infections, and BV here. If that’s not your issue, a workout and jaunt to brunch may be just fine. 

Don’t Wear a Thong While on Your Period 

Here’s a fun fact: menstrual blood is less acidic than your vagina’s natural state.

This means your vaginal pH is actually higher during your period. A less acidic environment can make it easier for imbalances in organisms, making you more prone to infections if things end up in the wrong place. 

While it is unlikely the sole contributor, if you find you have a yeast infection after every period, try skipping the thong to see if it helps. If it does, you have your answer about what works for your body.

Otherwise, no, there is no issue with wearing a thong while on your period other than it may not be adequate to support your flow.

Don’t Wear Thongs if you are Unwell 

If you have an infection in your digestive tract resulting in diarrhea, you may be passing infection-causing bacteria or viruses through your poop. Because transfer between your bum and your vagina or urethra could cause a new infection, better to not risk thongs while you’re already sick.

The Bottom Line on Your Bottom (or lack of) Coverage

Wearing thong underwear is your call. There's no science to show that they are as dangerous as some might have you believe, but that doesn't mean they couldn't be problematic for you.

Whether you choose thongs or other underwear, follow these tips to be mindful of your vulvar and vaginal health. Your underwear should make you feel good and be an informed choice you make for yourself! There’s nothing sexier than that.

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  1. Hamlin, Alyssa MD; Sheeder, Jeanelle MD; Muffly, Tyler MD. Brief vs Thong Hygiene in Obstetrics and Gynecology (B-THONG): A Survey Study. Obstetrics & Gynecology. 2018. 131.
  2. Runeman B, Rybo G, Forsgren-Brusk U, Larkö O, Larsson P, Faergemann J. The vulvar skin microenvironment: impact of tight-fitting underwear on microclimate, pH and microflora. Acta Derm Venereol. 2005. 85. 118-22.
About The Author

Dr. Jolene Brighten

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Dr. Jolene Brighten, NMD, is a women’s hormone expert and prominent leader in women’s medicine. As a licensed naturopathic physician who is board certified in naturopathic endocrinology, she takes an integrative approach in her clinical practice. A fierce patient advocate and completely dedicated to uncovering the root cause of hormonal imbalances, Dr. Brighten empowers women worldwide to take control of their health and their hormones. She is the best selling author of Beyond the Pill and Healing Your Body Naturally After Childbirth. Dr. Brighten is an international speaker, clinical educator, medical advisor within the tech community, and considered a leading authority on women’s health. She is a member of the MindBodyGreen Collective and a faculty member for the American Academy of Anti Aging Medicine. Her work has been featured in the New York Post, Forbes, Cosmopolitan, Huffington Post, Bustle, The Guardian, Sports Illustrated, Elle, and ABC News. Read more about me here.