How to Clean Period Underwear and Other Reusable Products, According to an OB-GYN

For every menstruating person who can’t bear to wear one more diaper-like pad, period underwear have been a lifesaver. They’ve gained more attention and traction in the last few years, with brands like Thinx and Knix taking the stage in period care. They’ve also been used for other purposes, such as bladder incontinence and postpartum bleeding.

For people who have been wearing tampons and pads for years, maybe decades, learning how to use and clean these new products can be a little confusing. Here’s what an OB-GYN wants you to know about cleaning period underwear and other reusable products to make them last longer and to keep you healthy.

Period underwear varies by brand, but most have the same basic technology, according to Dr. Amir Marashi, a board-certified cosmetic gynecologist, pelvic pain specialist, and the founder of Cerē. “The absorbent material collects blood, wicks moisture away from the skin, and eliminates odor. Some brands have a removable insert.” 

Knowing when to change to a new pair of panties can be difficult to gauge, since it doesn’t show how much blood is in them, unlike a pad. You’ll want to keep two things in mind: dampness and flow. “It is important to remove and wash the underwear once the skin begins to feel damp,” Marashi says. “Depending on how heavy the menstrual flow is, a woman might have to change her underwear several times per day. And different types of period underwear have different levels of absorbency. At the very least, I recommend changing them every 12 hours.”

The directions for proper washing and drying might vary slightly from brand to brand, but Marashi says for most types you can hand wash them or put them in a washing machine on a delicate cycle with cold water. When hand washing, rinse with cold water until the water is clear. Then, hang to dry. Some brands recommend avoiding the washer and hot water altogether. While it might seem hot water would kill more germs, it can actually set stains on the fabric, explains Marashi, essentially bonding the blood into the liner. And the last thing you want is last month’s period hanging around. 

Little research has been done on the impact period underwear has on an increased risk of yeast infection, bacterial vaginosis, or UTIs, Marashi says, “but it is well-established that prolonged/excessive dampness in the vulvar region can increase the risk of skin irritation (akin to diaper rash in babies), bacterial overgrowth, and potential infection.” 

He notes that it is important to eliminate excess moisture from menstrual blood to preserve the pH balance of the region. Additionally, you should make sure you’re not allergic to any of the materials used in the underwear. Try testing it when you’re not menstruating for at least an hour, suggests Marashi.

The options are endless when it comes to various period products you can reuse now, which will help the environment and save you money in the long run. Reusable pads can follow the same cleaning process as period underwear and can be hung dry or laid flat (they’ll also dry more quickly than period panties). Some recommend a 30-minute soak in cold water first before hand washing and using natural soap that won’t irritate your skin. You also might have to reshape the pad if you’ve used a washing machine before letting it sit to dry.

Menstrual cups, on the other hand, can be hand-washed with water and mild, unscented soap. To fully sanitize it, boil the menstrual cup at the end of your cycle (or at the end of each use if you prefer it). You can add diluted vinegar or hydrogen peroxide to the boiling water, but it’s not a requirement.

When in doubt, read the directions on the product thoroughly and follow those closely to preserve the integrity of your period panties, reusable pads, or menstrual cups for many cycles to come.