How Often Should I Change My Period Underwear?

Period underwear is just like regular underwear but specially built to absorb your menstrual blood. If you’re stumped about how often you should be changing them, we can help.

Period underwear is probably the best invention since air travel and the internet — yes, we’re biased — but that doesn’t mean that there isn't a learning curve when it comes to figuring out how to use them. Read on to learn more about period underwear and how often you should be swapping them out for a clean pair.

What is period underwear?

First, a quick refresher. Period underwear is just like regular underwear but it’s made with a special gusset (ours is made with 84% Modal, 8% Seaweed, 8% Spandex) that’s built to absorb period blood. Kt by Knix period underwear comes in three absorbency levels that you can swap out depending on your flow:

* Medium absorbency is best for light days and can hold 3 tsps (or 3 pads or  tampons worth) of blood
* High absorbency can hold 4-8 tsps (or 4-8 pads or tampons worth) of blood
* Super absorbency can absorb a whopping 9-12 tsps (or 9-12 pads or tampons worth) of blood.


You can peruse our selection of super cute period underwear here.

 A depiction of the three layers of absorbent material in period underwear consisting of an anti-odor layer, super absorbent moisture lock layer and a liquid-resistant outer layer

How often should I change my period underwear?


Short answer? It depends how you use it. 

Some people like to use period underwear as a backup for extra leak protection and wear it with a pad or a tampon. If that’s your style, change your pad or tampon whenever you need and treat it like a pair of regular underwear.

However, if you use period underwear as the main method of absorbing your menstrual blood, we recommend changing them whenever you begin to feel too wet, or notice any liquid sitting on top of the gusset. Period underwear is meant to protect you all day and can be worn for at least 8-12 hours, but it’s a good idea to swap it out after that.

Basically, how often you should change your period underwear depends entirely on what you're comfortable with. Our tip? Create a period survival kit for school  or on-the-go so you always have an extra pair to change into when you feel like it. As we always say, you know your body best.

Get our latests posts straight to your inbox.