Period Underwear: What to Know

Medically Reviewed by Brunilda Nazario, MD on July 21, 2021

What Is Period Underwear?

Today, there are many types of period products available. As you search for the one that works best for you, you may come across period-proof underwear. Anyone who menstruates can use these undergarments to comfortably protect themselves during their cycle.

These absorbent underpants have multiple layers of microfiber polyester. They look like regular underwear, but they’re designed to keep moisture away from your skin as they soak up menstrual blood.

The fabric in period underwear contains a moisture-wicking fabric made up of thousands of small filaments. These fibers trap liquid to keep it from leaking onto your clothes. The outer layer usually includes nylon and Lycra and is then finished with a liquid-repellent film to ensure your protection.

How to Use Period Underwear

When you start your cycle, you’ll use period underwear to catch the blood. You’ll put them on just like a regular pair of underwear.

It’s important to change and clean them at least every 12 hours, or as needed. Many brands come with an antimicrobial layer to get rid of any odor. But switching them out regularly will also help keep you fresh.

Washing instructions will differ based on the brand. Read the instructions before you clean your pair.

Who Should Use Period Underwear?

Anyone with a period can use period underwear. But it’s important that you know what to expect if you’re not used to free bleeding, which is a term used to describe when someone menstruates without the use of tampons or other common period products.

Period underwear doesn’t stop the flow of your period blood. If you use it, you’ll feel the flow of menstruation, which can be unsettling for some people at first.

Some women also use period underwear alongside other products, like tampons or menstrual cups, to add another layer of protection. But you can use period underwear by itself. Some brands come in different levels of absorbency, so you can choose a pair that works best for you on a particular day. Most pairs of period underwear are highly absorbent. But if your flow is heavy, it’s a good idea to check from time to time and see if you need to change them.

Benefits of Period Underwear

Unlike disposable period products, you can use period underwear more than once. Depending on the brand, period underwear can range from $24 to $65 per pair. If you wash them according to the instructions -- in the delicate cycle with no bleach -- your period underwear can last from 6 months to 2 years.

There’s no “right” period product to choose. Your decision should be based on your own personal comfort and well-being.

Show Sources


The University of Texas at Austin: “Period Products: The Good, the Bad, and the Ugly.”

Boston Children’s Hospital Center for Young Women’s Health: “Period Underwear.” “How Thinx Work,” “How to Wash Your Thinx.” “Period Underwear.”

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