Woman sleeping in white bra

If you keep your breasts supported in a bra when you go to bed, you may wonder what it’s actually doing to your breasts. Is it affecting circulation, is it putting you at risk for cancer, or is it actually preventing sagging? Well, none of the above. Let’s take a look at the negative effects of wearing a bra to bed first.

A study published in Cancer Epidemiology, Biomarkers & Prevention concluded that there was no risk of developing breast cancer associated with any aspect of bra-wearing, from the average number of hours worn daily, to whether the bra worn had an underwire, to the age at which a bra was first worn. In addition, there’s no proof that wearing a bra while sleeping leads to poor blood circulation (per Healthline).

But if you’re going to keep your bra on every night, be aware that there can be other effects. An improper, too-tight fit can lead to skin irritation, acne, and even unsettled sleep due to the discomfort. And if the cups don’t tuck under the breasts properly, it’s possible that fungal infection can develop in the fold, which may happen if skin is in constant contact with skin, as Dr. Regina Hampton, a board-certified breast surgeon, told Healthline.

Be sure you wash your bras often, as close-fitting undergarments tend to accumulate sweat, skin oils, and bacteria.

Are there any benefits to sleeping in your bra?

Unfortunately, just as there is no proof that nighttime bra-wearing causes cancer, there is nothing scientific to suggest that it keeps breasts from sagging. Attempts to prove that a bra prevents ligaments from "fatiguing" by offering additional support or, conversely, that its support allows breast tissue to grow weak and droopy have yielded no results (via Byrdie). Sagging may instead be caused by any number of factors, such as genetics, gravity, up-and-down weight changes, pregnancy and breastfeeding, menopause, and exercising without a supportive bra.

Still, there can be benefits to sleeping in a bra. If your breasts become painful around your period or during pregnancy, or you’re experiencing engorgement while breast-feeding or weaning, a soft bra can help reduce discomfort.

Even if none of the above applies to you, donning a bra in bed can just make you feel, well, comfy. The best choice for sleeping is one that’s soft, flexible, and wire-free. A cotton bra is good because it’s breathable. Finally, be sure it fits just as well as your daytime bra. Both breasts should fit entirely within the cups, with the center of the bra positioned flat against your chest. The back of the bra should be on the second hook and the straps should be adjusted for your body. Now that’s comfy enough to fall asleep in.