Here's How Often You Should Really Be Replacing Your Underwear

In this life, there are many great debates. There is, of course, the never-ending debate over whether pineapple on pizza is phenomenal or sacrilegious — ask someone from Napoli, Italy, and they'll clear that one up in no time. The great debate over how often you should change your sheets — ask a straight guy in his first semester of college and do the exact opposite. And, also up there on the list is how often you should be replacing your underwear. Because, yes, even the ones from La Perla that you spent way too much on have a shelf life.

But the problem with how often you should toss out your skivvies and buy new ones isn't exactly cut and dry. Some say every six to 12 months is about the time you should ditch the ones you have and get new ones (via Boody). While others say it's totally cool to keep them until — wait for it — they're falling apart.

"As long as you're washing and disinfecting your underwear, and they're mechanically functional, with no holes, and they're not soiled, you can keep those," professor of microbiology and pathology at the New York University School of Medicine Philip M. Tierno, Ph.D., tells Refinery29. "When they become frayed or the elastic stops working, you'll know to replace them."

Sure, this sounds plausible if we're talking about the granny panties you use when you have your period and usually have a liner in them, but what? Really? Let's dig a little deeper.

One word: bacteria

First of all, it's important to understand something about the human body: it's covered in microscopic creatures. Yes, creatures. It doesn't matter how much we scrub ourselves in the shower, those creatures — bacteria, viruses, and archaea, among other things — aren't going anywhere (via the BBC). Nor do we want them to go away; they're fundamental to our make-up.

However, these things can build up and create issues. An example of this is the perfect balance of candida and bacteria in the vagina that, under certain circumstances, can run amuck and cause a yeast infection due to overgrowth of that candida (via the Mayo Clinic). The same can be said of your underwear; build-up, despite regular washings, happens over time.

"In general, despite adequate and frequent washing of your garments, you should refresh your collection approximately every six months to avoid excessive bacteria build-up," reproductive endocrinologist, infertility specialist, and board-certified OB/GYN Taraneh Nazem, M.D., tells Well + Good. "In some cases, depending on the level of soiling, you may consider upgrading to new lingerie as soon as three months."

How to make your underwear last

If you can't afford to buy new underwear every three months or even every six months, there are at least some ways to extend the life of your underwear. For starters, never, ever wear them two days in a row, though 45% of Americans have struggled with this (via Fox29). That's just a bacteria party waiting to happen. 

If you've been working out, it's a hot day, or you're in any other situation that leads to sweating or even dampening of your underwear, change them throughout the day (via Healthline). Going through a couple of pairs of underwear when it's 90+ degrees outside isn't just healthy for your nether regions but also for the life of your underwear.

Every time you wash your underwear, use a detergent that contains peroxide, then crank that washing machine to the hottest setting possible. Also, wash your washing machine from time to time by running it on a bleach cycle with hot water — no clothes in it, of course. You can also adopt "the 50 wash rule," if you're willing to keep track of how many times you wash a pair of skivvies.

"I would say a maximum of 50 washes for a pair of cotton M&S underwear would be fine," consultant gynecologist at London Gynecology Narenda Pisal tells the Independent. "But obviously, if your underwear is causing chaffing, skin irritation, or is torn, you may need to do it sooner."

More than anything, it's about being aware of your body and knowing when to let go of your favorite pair of underwear. If you're currently sitting in undies that you wore to prom and you have to pause to do the math on how many years ago that was, then ditch 'em. Now. Your body will thank you later.