IMO, These Are the 8 Best Period Underwear—After a Decade of Trial & Error

• Absorbency: In the same way that tampons and pads advertise whether they’re suitable for a light, medium, or heavy flow, period underwear offers similar guidelines and typically states how absorbent they are in relation to how many tampons’ worth of liquid they hold. But, honestly, it may take some trial and error until you find the best fit for your flow, so if this is your first time free bleeding, it’s not a bad idea to keep a tampon or pad on hand.
• Fit and Silhouette: Period underwear comes in the same styles and cuts as our regular, everyday panties, so you can choose the silhouette you’re most comfortable wearing, whether that’s an itty bitty thong or full-coverage briefs. “Finding the right fit—especially when it comes to coverage and leg openings—can take some trial and error,” says Dr. Hack. Still, we recommend considering where you’ll be wearing them and what activities you’re performing. For instance, boxers are a great choice for sleeping, lounging, and working out because they provide the most coverage, but they might look awkward and bulky under formal clothing. On the other hand, though their slimmer silhouettes make them more susceptible to spillage, bikini-cut panties and thongs allow more freedom for working out or to go VPL-free in form-fitting silhouettes. 
• Material: If you’re sensitive to materials or commonly get yeast infections or irritation from your underwear, then the material of period underwear may make a difference. Family Nurse Practitioner in Dermatology Jodi LoGerfo, M.D., says, “I always recommend consulting with a professional in the medical field, your doctor, GYN, dermatologist when there are concerns about how your skin will interact with certain chemicals,” adding that because everyone’s skin is different, one person’s interaction will not be the same as someone else’s.
• OEKO-TEX Certified: “I recommend looking for certified labels, such as OEKO-TEX, which verifies that every fiber in the garment has been tested for harmful substances,” advises double board-certified gynecologist Monica Grover, D.O. There is a huge list of ingredients not allowed in order to be approved for the OEKO-TEX Certified labels, including pesticides, PFAS, heavy metals, and formaldehyde, to name a few. 
• PFAS-Free: “When brands claim ‘PFAS-free,’ they're typically saying one of two things: either they haven't intentionally added PFAS during manufacturing, or they've tested for common PFAS compounds below detectable limits,” says Rick Gillespie, Chief Commercial Officer of Revive Environmental, a full-service environmental contaminant mitigation and water treatment company. Neither guarantee is perfect. PFAS can contaminate products during manufacturing even when not intentionally added. “Testing for specific, target PFAS is available and many products can measure total organic fluorine, but limitations mean some PFAS compounds might go undetected,” explains Gillespie.

Are period underwear sanitary?

“Absolutely, as long as you wash them after each use to ensure they're hygienic and safe for you to wear,” says Dr. Grover. For proper hygiene, Dr. LoGerfo adds, “They should be changed at least every 12 hours or more often if needed.”

Do gynecologists recommend period underwear?

A resounding yes from Dr. Hack. “Period underwear has a lot of benefits—it can be a great option for someone who’s financially conscious. While the upfront cost is higher than buying pads or tampons, it can save money over time since it’s reusable. It’s also a great choice for anyone who’s concerned about the environment—single-use sanitary products create a lot of waste that ends up in landfills.”

“From a skin health perspective, period underwear can be a good alternative for those who find pads or tampons irritating,” she explained. Some people have sensitivities to the materials, fragrances, or absorbent gels in traditional products, and switching to period underwear (or a menstrual cup) can help. Most importantly, I’d recommend it to anyone who wants more options when it comes to managing their period.” 

Gunvor Ekman Ordeberg M.D., OB/GYN, co-founder of DeoDoc Intimate Skincare, also says yes, “I would absolutely recommend it, and I see that there is a big interest from women for period underwear.”

What are the drawbacks of period underwear?

Like any menstrual product, period underwear isn’t perfect for everyone. “Leakage is a common concern, just like with other period products,” says Dr. Hack. If it's your first time with period underwear and you feel unsure, it could be good to use as a backup for a tampon,” recommends Dr. Ordeberg. 

Period underwear contains some percentage of synthetic materials to be absorbent; people who are prone to irritation or yeast infections may do better with a 100 percent cotton pair, urges Dr. Ordeberg. “Some brands also contain PFAS (a group of chemicals you’d probably want to avoid), so looking for companies that test for and disclose their materials is a good idea,” Dr. Hack says.  

And finally, there is the upfront cost: As mentioned, over time period underwear may be cheaper than constantly buying pads and tampons, however, you still need to have the funds to purchase the pairs to see that benefit.

What is PFAS? And what do you need to know about PFAS in period underwear?

PFAS stands for per- and polyfluoroalkyl substances, which are a group of chemicals often referred to as “forever chemicals” because they’re nearly indestructible. “They contain carbon-fluorine bonds—one of the strongest in chemistry—making them highly resistant to heat, water, and oil,” says Gillespie. “This durability is why PFAS have been widely used in various consumer and industrial applications. The same properties that make PFAS useful also make them persistent in the environment. Unlike many chemical compounds that break down over time, PFAS remains intact for decades, accumulating in water supplies, soil, and even our bloodstream. Regulatory pressure is increasing stringent drinking water standards because studies have linked PFAS exposure to a range of health issues, including reduced immune response and cancer risks,” he explains. 

“Certain levels of PFAS have been associated with negative effects on reproductive health (decreased fertility), hormone disruption, an increased risk of certain cancers, and developmental delays in children, among other things. The vaginal mucosa is absorbent, and may readily absorb these chemicals,” Dr. LoGerfo says. 

However, research is still ongoing, and there isn’t enough evidence to confirm the level of exposure that will lead to these adverse effects. While some period underwear brands were accused of utilizing PFAS in their materials, the unfortunate reality is that many consumer goods (including tampons and pads) contain PFAS as well, according to Dr. Hack.

Shannon Bauer is InStyle’s associate editorial director and has 10 years of experience as a journalist covering beauty and fashion as well as testing and writing product reviews. She has also used period underwear for the last decade, up to 40 different brands and styles. Shannon took her own experience with products as well as analyzed results from our testers to create this list of the best period underwear. She interviewed: 

• Dr. Stephanie Hack is a board-certified OB/GYN physician with over 15 years of experience. She hosts the educational podcast “Lady Parts Doctor,” and several television and radio shows.
• Dr. Gunvor Ekman Ordeberg M.D., OB/GYN, is the co-founder of DeoDoc Intimate Skincare.
• Rick Gillespie is the chief commercial officer of Revive Environmental, a full-service environmental contaminant mitigation and water treatment company. 
• Dr. Monica Grover is a double board-certified physician in gynecology and family medicine, specializing in women’s intimate health.
• Dr. Jodi LoGerfo is a family nurse practitioner in dermatology. 

Additional reporting was done by InStyle writer Irene Richardson.