despite adequate and frequent washing of your garments, you should refresh your collection approximately every six months to avoid excessive bacteria build up.
Wear a fresh set of underwear before going to bed or after a shower rather than the same pair you have been wearing all day. For workouts, you may consider wearing underwear that's well-fitted and absorbs moisture. And just like you might change out of your sweaty gym clothes after a good workout, your underwear should be changed too.
It’s important to note that the 6 to 12-month recommendation is just a guideline, and there isn’t an exact science to determine how long your underwear will last. Instead, there are several signs you can look for if you think it might be time to say goodbye.
Stretch – The elastic around your legs and waist will lose its give over time. If you notice that your underwear has lost its stretch, it’s time to move on to a new pair.
Fit – Once the stretch is gone, your underwear won’t have the smooth, glove-like fit you want them to have. Saggy underwear isn’t comfortable, nor are they an attractive option under your clothing.
Frequency of wear – The underwear you wear more frequently is more likely to accumulate bacteria than those you only wear on special occasions.2 The risk for serious health problems is low, but you’re better off avoiding infection altogether by replacing your regular rotation often.