What Is Period Underwear and Does It Work?

You may have seen ads on social media or maybe you’ve heard your friends talking about them, but you’re still confused on what exactly period underwear do and how they work.

A new kind of period product, period underwear is designed for those who menstruate. Like pads, cups and tampons, the goal of period underwear is to keep you leak-proof and dry. Absorbing blood from your menstrual cycle, period underwear comes in different absorbency and are reusable (you can clean most brands in your washer).

Ob/Gyn Karmon James, MD, shares how period underwear work, what to look for and why they might be a good option for you.

How do period underwear work?

While there are many brands to choose from, most of them use some type of absorbent material like microfiber polyester that traps your blood flow. Period underwear typically have a moisture barrier to keep you feeling dry and a layer to help prevent leaking. Some brands even apply an odor-controlling treatment.

“Period underwear typically holds somewhere between one and two tampons worth of flow,” Dr. James says.

Are they sanitary?

Yes, as long as they’re washed properly. While you can handwash them, period underwear can also go in the washer, using the gentle or delicate cycle.

Make sure you wash your period underwear on their own and avoid placing them in a load with other clothes and items. Avoid using any fabric sheets or fabric softener, too.

“Use a mild, unscented, dye-free detergent,” says Dr. James. “Do an extra rinse cycle because you want to make sure that there’s no laundry detergent left on them. That could be irritating to your skin otherwise.”

When it comes to drying your washed period underwear, air-drying is best.

Most pairs can typically last between two and five years, says Dr. James. But it depends on the quality of the product and how often you wash them.

How to use period underwear

Period underwear fit and function just like normal underwear. Just put on a pair when you’re menstruating. You can wear them alone or if you’re using a tampon, they can be used as an extra form of protection.

If you’ve used tampons for much of your life, you may need to get used to the feeling of your menstrual flow.

How long you can wear period underwear depends on your flow. If you’re having a light flow day, you can probably wear them longer, but if your flow is at its heaviest, you may need to change your period underwear more frequently.

It’s recommended that you don’t wear the same pair for more than 12 hours to avoid odor and leakage. You may need five to seven pairs of period underwear to wear throughout your cycle.

While intended for your menstrual flow, period underwear can also be used for urinary incontinence, discharge and postpartum bleeding.

“If you’re wanting them purely for urinary leakage, then you should focus on a product that’s designed for that,” notes Dr. James.

What to look for

If you’re curious about whether period underwear is right for you, Dr. James suggests testing out a pair on your lightest flow day.

“Try them on a weekend or when you can be at home,” says Dr. James. “If they don’t fit properly or you have a leak, you’ll feel more comfortable handling those issues at home.”

Then if you decide you’re all in on wearing period underwear, test out a few different brands before investing in a whole new set of underwear. Do your research before any purchase. What absorbency do you need? How are the brand’s online reviews?

“See if there’s one that fits you better or is more absorbent,” advises Dr. James.

In addition to deciding if period underwear work for your body and your menstrual flow, there are other factors one should consider.

If you’re concerned about the environment, period underwear can help cut down on waste. It’s estimated that the average menstruating person uses up to 15,000 pads or tampons in their lifetime.

If you experience irritation from using traditional menstrual pads, switching to period underwear may help.

There’s also a case to be made that using period underwear can save you money, says Dr. James.

“You need to look at the cost of underwear, the cost of pads and figure out if it’s a benefit for you,” she says.

But overall, you need to make sure you feel confident and secure using period underwear.

“If the underwear is doing what it should be doing, you should feel comfortable,” says Dr. James. “They should keep you dry and protected.”