How Do Period Underwear Work? Your Biggest Questions, Answered

September 01, 2023
Team Knix

Periods are personal—we cultivate habits and rituals around our periods that allow us to bleed comfortably and in ways that conform to our unique bodies. There's truly no one-size-fits-all approach. 

Over the past decade, period products have undergone somewhat of a renaissance with the introduction of reusable options, like menstrual cups and period underwear. But if you've been a lifelong tampon or pad user, the notion of making a change to your well-oiled period routine might seem daunting. 

If you're considering trying period underwear but have some questions, you've come to the right place. We're pretty sure you're going to love having Leakproof garments but, first, we want to answer your biggest queries.

Ahead, you'll find answers to our most asked questions period underwear-related questions.

Wait, so how does period underwear work?

Leakproof High Rise Thong in Cobalt display: full

Our period underwear is designed with multi-layer technology that varies from style to style, but works to ensure you stay fresh, dry, and protected. For instance, in our Super Leakproof No-Show Bikini, the top layer wicks away moisture, absorbs and locks in liquid, while the outer layer prevents any moisture from spotting on your clothes.

The latest period underwear innovations feature an ultra-thin liner that absorbs menstrual blood, light urine leaks, and sweat with the addition of a special seal that locks in leaks at every edge.

In short, period panties are designed to be comfortably worn all day long. Period underwear can be worn solo or as back up protection, this just depends on your preferred absorbency, as well as your unique menstrual flow.

You can use period underwear in whatever way works for you, whether in combination with another period product, like a tampon or menstrual cup, or on its own.

Are period underwear bulky?

We would never let you walk around feeling like you're wearing a diaper or bulky pad. In fact, period underwear should feel like regular underwear, except they have a thin, absorbent liner.

No one should have to sacrifice comfort or style on their period, which is why our period underwear look seamless under clothes and come in assortment of styles—from thong to high rise. But what about high rise thongs, you say? Yep, we even have those too. 

Can I use period underwear solo?

To be honest, how you use period underwear will depend entirely on your unique preferences and period flow. When it comes to wearing period underwear, there are no wrong answers.

Period underwear come in a range of absorbency levels, from light period underwear to super absorbent period underwear. Designed to keep leaks at bay during every phase of your period, you should pay close attention to your absorbency needs.

Light Leakproof, for example, can be used as full on protection on lighter flow days or as backup protection alongside tampons or menstrual cups on your cycle's heavy flow days. If you're looking for full coverage throughout your period, Super Leakproof styles are designed to absorb the equivalent of multiple super tampons worth of menstrual fluid.

When it comes to finding the perfect fit and absorbency level, consult our absorbency guide to find the perfect pair of period underwear based on leak types, your unique flow, and fit preferences.

How long can I wear period underwear for?

Lace Leakproof Bikini display: full

That's up to you! While period underwear are designed to be worn all day, this can depend on your unique period needs.

On heavier flow days when you're relying entirely on Leakproof protection, you may wear period panties for a shorter period of time, whereas on lighter flow days that same pair can be worn the whole day through. That said, period underwear are designed to be worn comfortable for long stretches of time.

The more absorbent, generally, the longer period underwear can be worn. For overnight or full 9-5 protection, Super Leakproof undies are among the most absorbent period panties. Of course, the period underwear that work best for you will vary depending on your body's unique rhythm.

As when it comes to trying anything new, it may take some experimenting to get the exact formula down.

What about blood clots?

Blood clots are a natural part of your menstrual flow. If it's something you're worried about, you may want to opt for a pair of Ultra Leakproof undies—this style features our highest absorbency lining and should be able to absorb small clots.

In the event you have a bigger clot, you can always pluck it out of the lining with some toilet paper and carry on with your day.

Can I wear period underwear to sleep? 

Since tampons generally shouldn't be worn more than eight hours without being changed (due to risks associated with Toxic Shock Syndrome), period underwear are a great alternative to pads when it comes to catching zzz's. 

In fact, our Super Leakproof Dream Short was created just for that. Do they work for non-blood related leaks, too? Absolutely! While we tend to emphasize their period-related uses, Leakproof Underwear can be used for leaks of all sorts—including blood, sweat, or pee.

Whether you're looking for support with postpartum incontinence or want to workout intensely without the sweat marks, period underwear is your friend. 

In fact, beyond just our Leakproof Underwear offering, we have specially-designed period pants and leggings, in the form of LeakStrong Activewear, designed for maximum movement and comfort, sans leaks.

Does that mean I can go commando while working out?

LeakStrong Leakproof Legging in Dahlia display: full

Since Leakproof technology is built directly into our assortment of period pants, shorts, and skorts, like our LeakStrong Leakproof Legging and Leakproof Skort, you should be able to go entirely underwear-free, if you wish!

Do period underwear get smelly?

This is a valid concern but, generally, if washed regularly and properly, your period underwear isn't at risk of becoming odorous. More details on that below!

How do I wash period underwear?

To avoid any odour, you'll want to wash your period underwear after each use. Before tossing them in the washing machine, we recommend a preliminary rinse in the sink or bathtub.

From there, you can machine wash your period undies with cold water using mild detergent (no bleach!). The final step is laying your period underwear flat to dry, but you can find more detailed instructions here.

What if I try period underwear and it’s not for me?

Leakproof Bikini display: full

That's okay, too—and you should feel proud for stepping out of your comfort zone and giving period undies a try. Our 30-day exchange policy means you can give period underwear a whirl and decide whether or not they're for you before opting for an exchange or store credit. 

We hope you found this post informative—but remember: we’re not doctors and this post is not medical advice! While all posts are fact-checked and well researched, we always recommend you chat with your doctor about any questions or concerns you might have regarding a medical condition. 

We’re here to support and educate, but never with the aim of disregarding professional medical advice you’ve been given. Phew, now that that’s out of the way, you can go on living unapologetically free.