Your bath towel is hiding a dirty little secret—a weekly wash isn’t enough to keep it clean.
You only use your towel after scrubbing off in the shower, so it can’t get all that dirty, right? Not so fast. “When you say you wash off bacteria, you’re partially correct—you wash off some bacteria,” says Philip Tierno, PhD, clinical professor of pathology and microbiology at NYU School of Medicine. But others will stick around, and they get on your towel during your post-shower rubdown.
Once those bacteria are on there, they’ll start to multiply. “It keeps building up as you use the towel again day after day,” says Chuck Gerba, PhD, microbiology professor at the University of Arizona. A study led by Dr. Gerba found that used hand towels have 1,000 times more coliform bacteria than newly bought ones. Bacteria love dark, moist environments, so they’ll thrive in a steamy bathroom with the door closed.
Rubbing down with a dirty towel, and you could be at risk for infection. “When you use a towel vigorously, you scratch your skin,” says Dr. Gerba. Those tiny breaks in your skin—which are too small to notice—give bacteria an entryway to get in your body.
Still, it’s “extremely unusual” to actually pick up a disease from your bath towel, says infectious disease specialist Aaron Glatt, MD, FACP, FIDSA, FSHEA, spokesperson for the Infectious Diseases Society of America and chairman of medicine and hospital epidemiologist at South Nassau Communities Hospital. Your own germs won’t make you sick, but you up your chance of picking up a disease when you share towels, says Dr. Gerba. (Find out why you shouldn’t share a loofah either.)
Even if you don’t let anyone else touch your towel, Dr. Gerba and Dr. Tierno recommend washing bath towels every two or three days. Hold out longer than that, and all those microorganisms will make your towel grungy. “You may not get sick after using a towel for two weeks, but that’s not the point,” says Dr. Tierno. “Would you put on dirty underwear (unless there’s an emergency) after you’ve taken a clean bath? It’s very similar to what you’re doing after the first couple of drying episodes.” While you’re at it, don’t forget to wash these other items you don’t clean enough.
If you’re acne-prone, you might want to wash your towel every time you use it, says Dr. Tierno. As you rub your skin—especially open pustules—with a dirty towel, bacteria could get on your skin and give you zits. Get rid of pimples on your body with these bacne remedies.
Between washes, cut down bacteria growth by letting your towel air-dry fully, says Dr. Tierno. Instead of folding it, drape open on the rod. The more surface area is open to the air, the better it will dry. If you have a heated towel rack that speeds up dry time, you might only need to wash after four uses—but that’s “pushing it,” says Dr. Tierno.
Even though you might need to do more laundry, don’t get lazy. Bacteria aren’t in a rush to leave a thick cotton towel. “It’s really hard to clean those towels,” says Dr. Gerba. “Even with hot water, you have to go through a full cycle to remove them all.” Once it’s out, leave it in the dryer for at least 45 minutes to make sure all the moisture is gone, he says.
MORE: How Bad Is It To Not Wash Your Sheets Every Week?