Over time the elastic in the waistband eventually wears out, causing it to lose its shape — and potentially fall off your body. The same goes for your brassiere. “If your bra is no longer stretchy in the straps or back, it won’t offer the proper support,” says Lexie Sachs, a textiles product analyst in the the Good Housekeeping Institute.
Because underwear is washed so often, shrinkage can be expected, especially if it’s made of cotton. You don’t want to cut off your circulation, so ditch any too-tiny briefs.
When it comes to your bra, your breasts probably change way more than you realize, so that bra that was once a perfect fit might be causing you some problems including back pain, and even saggy boobs. Look out for spillage, a band that doesn’t lay horizontal, and tightness even on the last hook — all signs your bra is too small.
This should be a given, but if you have a pair of undies that just don’t feel right — throw them away. Especially if you’re a fan of the lacy version, which after multiple washes can get rough and potentially cause cysts and irritation, warns Mona Gohara, M.D., and Associate Clinical Professor of Dermatology at the Yale School of Medicine.
If the padding or cups of your bra shift and rumple, it’s time to buy a new one, says Sachs. The last thing you want are gaps or bulges — your cups should align with your breast. Otherwise, you’re not getting the support you need, which is why you’re wearing a bra in the first place.
Even though your undergarments might now show these signs of wear and tear right away, you should still plan to replace them every six months to a year. The good news? If you frequently rotate your bras, you can make them last much longer.