2 Underwear Questions You’re Too Embarrassed to Ask (But We’re Not!)

1. How bad is it to do a second day in the same undies?

We have good news for anyone who’s skipped a laundry day: As far as health is concerned, it’s not a huge issue to wear the same pair of underpants 2 days in a row, says J. Scott Kasteler, MD.

That is, as long as those undies are clean to the eye (unmarked with urine or stool). From a health standpoint, you could go several days without a fresh pair, Kasteler says.

But before you wear your “Monday” pair on Tuesday, consider two important exceptions.

If you have any scratches, sores, or rashes on your skin, don’t stretch the mileage on your underwear or you could end up with an infection. And if you’re breaking a sweat, it’s best to don a fresh pair. For folks with vaginas, moisture buildup in the nether regions can lead to yeast infections.

While those with penises may not be as susceptible to infections, it’s still a best practice to keep the area nice and dry. It’s just not worth the risk of chafing below the belt. (Hey, there’s a reason swanky gyms have spare pairs for sale.)

2. Does fabric matter?


The quick answer is yes. Your underwear fabric can make a difference for your health.

To prevent no-fun down-south issues like rashes, vulvovaginitis (an infection in the vagina or vulva), or jock itch, health experts suggest wearing new, clean, well-fitting pairs of cotton underwear to allow for breathability and to absorb moisture that can be a catalyst for infection.

Fabric that wicks away moisture has also become popular as a base layer for outdoor athletes, especially during the winter.

Underwear with wicking fabric (polyester or a polyester blend) can reduce moisture in your neither regions during long days on the slopes (or when you’re just huffing it to the train).

A small 2015 study found that people who wore these synthetic fabrics saw improved athletic performance and comfort over wearing cotton fabrics.Trusted Source (If you’ve ever run a marathon in a cotton T-shirt, you’ll understand why this makes sense.)

But it’s still a good idea to change your undies after a sweaty workout to minimize the risk of infection.