For some reason, throwing away undies and bras feels a bit wasteful. Even when they’ve been in your rotation for a solid amount of time, it’s still tough to toss your tried-and-true essentials. We figured we couldn’t be the only ones experiencing this strange separation anxiety, so in this installment of Asking for a Friend, we take a deep dive into the world of underwear care. Keep reading to find out the exact shelf life of our undergarments, when we should replenish our supply, and how to extend the life of our current collection.

How Often Should I Buy New Underwear?

There are a few factors to consider when gauging the lifetime of your bras and panties. As a general rule (and the industry standard), your underwear assortment should be refreshed every six months to a year. However, you also have to consider how many core pairs and styles you have in your rotation. If you tend to buy individual undies throughout the year, just be sure you’re also discarding older ones as you go. When it comes to bras, it really depends on how many you wear regularly. “You want at least three — one to wash, one to wear, one to spare,” says Alicia Miller, fit expert at Chantelle. She adds that this count doesn’t include specific solution pieces like strapless bras and sports bras.

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How Do I know when it’s time to replace my underwear?

Tell-tale signs of worn out undies are stretching and fading. If you feel like they’re no longer gripping your hips and are shifting around under your clothing, it’s time to trash them. Your bra’s expiration can be tougher to measure, especially because women often aren’t wearing the right size to begin with. “Go out and get properly fitted to make sure you’re in the right size, I can’t stress this point enough,” says Miryha Fantegrossi, vice president of merchandising and design at Wacoal. “Even something as small as plus or minus five pounds can change your bra size.”

A brand new, well-fitting bra should be worn on the loosest hook. Over time, the material stretches and you have to tighten it up using the other hooks. Once you notice you’re finally on that last hook, the straps feel stretched out, the bra’s neckline has loosened, or there are any fraying fabric or underwires poking out — you’re ready for a new purchase. Overall, if you’re not feeling as supported as you once were, it’s time to say goodbye.

How should I care for my undergarments?

“Your lingerie bag and delicate wash cycle should be your best friends,” says Eunice Lee-Meldahl, GapBody’s design director. It might seem like a lot for your everyday, cotton undies, but if you really want to extend their life, always wash in a bag on a delicate, cool to warm water cycle. When you’re caring for really dainty styles, use delicate detergent and wash by hand in room temp water. Lee-Meldahl recommends swirling them around and then letting them soak for 45 minutes before carefully rinsing them out. “Your best bet is to also air dry your undies and lay them on a towel to soak up excess water,” she says. “This will lengthen the life and keep the lace or other fabric in better shape.”

Always hand wash your bras, too — especially if they have underwires. “Spin cycles and heat can warp wires (even after just one wash!) and [detergent] can fray fine fabrics,” says Marissa Vosper, co-founder of Negative Underwear. If you do end up using a conventional washer for underwire-less bras, be sure to close the back hooks, use a wash bag, and set the washer on a slow speed gentle cycle. Avoid the dryer and lay your bras flat to dry to avoid stretching out the straps and centerpiece from hanging or draping. In addition to adopting proper wash and care etiquette, Vosper says that rotation is of equal importance. “Most of us are guilty of that phase where we only had one or two bras we actually wear daily,” she says. “When you find a bra you love, buy multiples and rotate wears. That’s the best way to keep your bras in good shape for longer.”

RELATED: How Do I Keep My Nipples from Showing Through My Clothing?

(Photo via Getty; Illustrations by San Trieu)

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