How often do you really have to wash your bra? Science answers I sent my dirty bra to a microbiology lab. The results were both comforting and horrifying.

Over the past few months I've discovered that I have a dirty little secret—a secret that, until very recently, I didn't even realize was dirty. Or should be kept secret, for that matter.

Please try not to judge, but I do not wash my bras regularly. Like, at all. I used to rotate wearing around five bras, washing the dirtiest every two to three weeks. But I've let my habits slide. Between being pretty busy, suffering from general ennui when not busy, and hating the feel of a newly washed bra—I now go months without washing them.

The thing is, until this past summer, I thought this was pretty normal. Like jeans, which many brands explicitly advise against washing, I'd convinced myself that my bras were somehow immune to the filth that accumulates on other items of clothing after just one wear. But after an enlightening discussion with colleagues about their personal bra-washing habits amid the sticky heat of July, I began to have doubts.

These doubts only grew when we polled readers about bra-washing regimens. The majority of you claimed to wash your bra somewhere between every week and every three to four wears. Sure, some of you confessed to washing yours less frequently, explaining that "excessive washing will ruin bras"—but by my standard, you cleansed them pretty damn often.

Personal pride aside, though, does it really matter how often you wash your bra? I mean, yeah, they're dirty, fine—but am I causing myself or others harm by not washing them? Could my bras be harboring some dangerous bacteria or something I don't know about? Am I promoting the growth of a horrific disease that will soon become responsible for a non-viral zombie apocalypse? Or worse, flubber?!

As a public service, I decided to ask three bonafide microbiologists about proper bra care. The results were both comforting and horrifying.

I began by reaching out to Philip Tierno, a professor of microbiology and pathology at New York University's School of Medicine, who has become something of a go-to expert for revealing the hidden germs that lurk in everyday objects. "A bra should receive the same treatment as any other underwear," he told me. "It should be washed daily or at least every other day." Wow. Okay. Got it.

And yet, he did note that since bras aren't usually shared, they don't pose much of a health risk, at least in terms of transmitting bacteria. Good thing no one's asked to borrow my disgusting unwashed bras!

Next I spoke with Michael Schmidt, a professor and vice chairman of microbiology and immunology at the Medical University of South Carolina. He went into more detail about what, exactly, may be happening on a microscopic level.

"[With] daily wear for months—the garment will become soiled with the oils of the wearer that in turn will serve to support the growth of microbes from the skin, that have transferred to the fabric," he told me over email. Okay, gross, but what else?

"By not washing for months you will likely see the emergence of ‘opportunists,' microbes that normally don't associate with people," Schmidt wrote. "If the skin of the wearer is unbroken, and they are healthy, the ‘new microbes/opportunists' should not cause any problems…as long as the wearer has hygienic practices." Schmidt hypothesized that the microbes would likely include staphylococcus, and possibly the more ominous streptococci.

While I breathed a sigh of relief that I have no open wounds in my bra region, I wanted more. Forget the hypotheticals—what tiny opportunists were camping out near my boobs? And so, last week, I shipped my dirty bra to William Helmink, the director of microbiology at the University of Toledo Medical Center, who graciously agreed to run cultures on it.

The last time I had washed the bra was on August 29, more than two months before the test.

Helmink chose to test four areas of the bra that he considered bacterial hotbeds: the underwire of the left and right breast and the parts closest to the left and right armpits.

"I moistened a swab with a sterile solution and then rubbed it on the sections," Helmink explained over the phone. He then put the swab in a liquid solution. "I used an enrichment broth to see if there were any organisms there. If they grow, then I grow them on a plate."

The result? Indeed, my bra specimen tested positive for coagulase-negative staphylococcus.

"The result was pretty consistent with normal environmental and skin flora," Helmink said. Thankfully, it did not include any pathogens or extraterrestrial Andromeda Strains.

Still, the bacteria does look pretty gnarly in photos.

Coagulase-negative staphylococcus.

Helmink cautioned that the images make the organisms appear scarier than they actually are, though I suspect these bad boys will haunt my dreams. Honestly, even though these are totally typical bacterial growths, I do feel a bit scared straight.

So what have we learned today? Well, just because you can avoid washing your bra for more than 60 days without causing an outbreak doesn't mean you should. Because things do grow on your bra, and they are nasty. So wash your bras every few wears—and when you do, try to wash them by hand, always use cool water, and keep that beautiful thing out of the dryer!

And if it's been a while since you last washed your bra and you're not sure if you're ready to part with your filthy source of support, consider the wise words of South Carolina's Schmidt: "Let your nose be your guide. If it smells like the gym, it's time for the laundry."

Sorry! Comments are disabled.