How Often Should You Change Your Period Underwear?

You know the drill with tampons. You’ve read it on the box a million times. Leave it in for more than eight hours and something horrible happens! The sun explodes, or you’re cursed with seven years of bad luck or whatever else comes to mind when you hear the words: “toxic shock syndrome.”

But what about period underwear? How long can you safely, hygienically wear a pair? 

The short answer is all day long, but there’s a bit more to it than that. Period proof underwear can vary by style, absorbency level, and coverage. Plus, you already know your cycle can change a lot from day-to-day and period-to-period.

That means that, like trying anything new, it may take a bit of experimenting to understand how often you need a fresh pair for your unique flow. Below, we’ll go over when to change your period panties, and how to best prepare for all-day wear.

Understanding How Period Underwear Works

The multiple absorbent layers in Knix Leakproof Underwear can absorb anywhere from about one pantyliner to nine super tampons’ worth of blood, depending on which style and level of absorbency you choose. To get the maximum hours out of your period panties, you’ll want to choose the right coverage style with the right absorbency you might need, depending on your flow that day.

To choose the right absorbency when selecting any of Knix Leakproof products, head to the product page and click the Leakproof Guide link on the right hand side. There, you’ll see exactly how much liquid each product is designed to absorb, plus its equivalent in pantyliners, tampons, super tampons, and menstrual cups.

Knix Leakproof absorbencies range from Light (think: daily use for discharge or light spotting) to Ultra (think: heaviest day of your period.) They also have Medium and Super absorbencies in between, so you can easily find one that’s right for you.

In addition to absorbing up to a full day’s worth of heavy bleeding for many people, Knix period underwear can also help keep wearers feeling dry. The modal layer of fabric in many styles of Knix pulls moisture away from the body, so period panties can feel fresher against your skin for all-day wear. 

With a strong enough absorbency, many people can wear period undies all day and only need to change them before bed. Leakproof Underwear is designed for all-day wear, but depending on your flow and which day it is in your cycle, you might find you need to change your period underwear a little more often. 

What Period Underwear Absorbency Should You Opt For on a Light, Medium, or Heavy Day?

On lighter flow days, you might find that Knix’s Light absorbency is perfect. However, if you’re worried a heavier period might sneak up on you, Medium can offer extra absorbency. On medium or heavier flow days, opt for a pair of Medium or Super Leakproof underwear. 

Other folks might feel more comfortable combining an insertable with their underwear for periods. Everyone’s flow is different, so what’s heavy to you may be light to someone else and vice versa. Experiment with different absorbency levels to see what works best for you on different days of your cycle.

For overnights or extra heavy days, Super Leakproof Dream Shorts are a popular option. They’re a safer alternative to insertables (like tampons or discs) for overnight use. Knix sleep shorts are designed to go the distance, whether you can’t get to a bathroom or don’t want to get out of bed.

What’s the Longest I Can I Wear My Period Underwear?

Period underwear are designed to be worn all day or all night. For hygienic purposes, period underwear should be washed after daily or overnight wear.

Tips for Staying Comfortable in Period Underwear

You’ll know better than any internet guide when it’s time to change your period underwear. Just listen to your body. Everyone’s flow is different, so pay attention to signals like cramping or clotting to know when you might need a fresh pair.

One recommendation from the Cleveland Clinic is to test out period panties on your lightest flow day, and try them on a day where you’ll be at home and can handle leaks or underwear changes more easily. As you get used to period underwear and understand how they feel on your body and how much of your flow they absorb, you can start to wear them out on the town or on your heavier days.

One nice thing about Knix is that, as long as you’re within that one-day (or one-night) window, you don’t need to worry about odor. A moisture-wicking layer and patented odor-neutralizing technology mean no one else will know what’s going on down there.

Caring for Your Period Underwear After Each Wear

Regardless of how long you wear them, your period underwear needs to be washed after every single use. It’s up to you (and your flow) whether you want to just chuck them in the washing machine or if you need to give them a good rinse before that first spin cycle. 

Either way, to wash your period panties and keep them in great shape:

• Machine wash them on cold
• Use mild, ideally unscented, detergent
• Don’t use bleach
• Lay them flat to dry

It’s a good idea to wash period panties as soon as possible after you use them, so they aren’t sitting around in a laundry basket collecting odors or staining your other clothes. Don’t worry–washing your period underwear with other clothes won’t stain them.

Generally speaking, if you use period panties every day, you’ll need two clean pairs for each day of your period—one for daytime and one for nighttime—plus a backup. Factor in specific outfits and styles, plus how often you do laundry, to figure out exactly how many you need. 

A pair or two, or the Heavy Flow Kit, can be a good starting point. Most people choose to own somewhere between 3-7 pairs of period panties in total, but it depends a lot on your flow and lifestyle.  

It’s also best to try period underwear in a range of absorbencies, as you figure out the best styles for your body. Start with just a pair or two, so you can try out different styles and figure out which ones work best for you. 

Ready for a More Comfortable Period?

Once you find the right absorbency for your flow, period underwear can keep you feeling confident all day. Period underwear is designed for all day or overnight use, but let your body and your own comfort levels tell you if you need to change your period underwear a bit more often.

Remember, everyone’s flow is different, and we all have different preferences about how light and dry we want to feel. It might take some experimenting, but with the right style and a little bit of practice, you’ll find the right number of changes for you.