Pick a breathable fabric, like cotton or a cotton-rayon blend. Bras cut from synthetic materials, such as nylon or spandex, can irritate skin as well as block air circulation, triggering redness and/or itching if worn regularly. Occasionally wearing a sexy, lacy one (typically made with nylon and spandex) won’t cause any harm.
Look for molded cups. A bra that lets your boobs bounce as you move can worsen PMS breast pain and cause soreness and possibly even sagging.
Wash it the right way. As tempting as it may be to let the washer and dryer do all the work, the cups and band will stay firmer and give you more support if you wash the bra by hand with a mild laundry detergent in lukewarm water and let it air-dry after each wear.
Lose it when it feels loose. There’s no hard-and-fast rule as to how long the average bra lasts, but it’s a good idea to stop wearing it when the elasticity begins to give and/or you’re constantly adjusting the straps to make it fit.