What Is Period Swimwear?

Perhaps you’ve heard internet chatter about period swimwear, or maybe some of your girlfriends are already using it and raving about it. You’re intrigued but not quite sure you understand what period swimwear is and how it works. Let’s clear that up for you!

Period swimwear looks on the outside like a regular swimsuit. It comes in different styles (one-piece, bikinis, and everything in between) and colors. But it has one key difference from regular swimwear: It is designed to absorb and hold period blood as an alternative to traditional period protection, like tampons. 

Yep, you read the right. This seems like a mind-blowing proposition. How does a swimsuit hold the blood without leaking? The secret is in fabric technology. 

Related: How to get period blood out of swimsuit bottoms

How Does Period-Proof Swimwear Work?

The layered fabric in the gusset of Knix leakproof swimwear traps and absorbs menstrual blood, so it doesn't leak in the water (or on land!) Our Swimwear features the same Leakproof Technology as our Period Underwear with an additional thin layer of waterproof material for extra protection.

The inner layers absorb the blood and trap it, so there's no leakage when you swim. When it goes in the laundry with detergent, it releases through the top layer— leaving your swim fresh and clean for tomorrow's laps.

Can Period Bathing Suits Be Used With a Menstrual Cup or Tampon?

It’s entirely your choice. Some women prefer to double up on protection and pair their period-proof swimwear with a disposable tampon or reusable menstrual cup as backup protection. This can especially give you confidence on your heaviest flow day or while you’re getting used to depending on your period swimwear. If you already use tampons or menstrual cups, this is a great way to ease period swimwear when on your period. However, you shouldn’t need to depend on additional products. 

Is Period Swimwear Suitable for Heavy Periods?

Our period-proof bathing suits are suitable for heavy as well as light period days.

Of course, some people have very heavy periods and may experience clots and ‘gushing’ blood. (Aside: If this is the case, please do discuss your periods with your doctor.)

You know your own flow better than anybody else, and you're also the best judge of your own menstrual cycle, so if you are worried that period swimwear may not hold your flow, you can use it as a backup product in conjunction with tampons or menstrual cups.

Is Period Swimwear the Same as Period Underwear?

Period underwear and period swimwear share a lot of the same technology. However, there is one important difference: Period underwear is not designed to be worn in the water. This means that you can’t simply swap those period-proof bikini bottoms for period underwear in a similar style. They may look identical, but one is designed to wear in the water, and the other is not. 

Can Anyone Tell if You’re Wearing a Period Swimsuit?

Period swimwear is designed to look just like regular swimwear. Across brands, it comes in many different styles and colors. You can find:

• Two-piece swimsuits or one-piece period swimwear bottoms
• A variety of colors and patterns
• Simple maillot-style swimsuit, or ones with details like ruching, cut-outs, or wraparound
• Bikini bottoms that are classic bikini style, high-rise or boyshorts style
• Swimsuits with other details like built-in shelf bras and removable cups
• And so much more…

You may notice a slightly thicker gusset on your period swimwear. However, it will not be noticeable to other people, and you’ll likely forget it altogether once you get the swimwear on. Nobody will know the difference between your period swimsuit and any other swimsuit you might pick. Indeed, you might find yourself reaching for your period swimsuit even when you don’t have your period (which is excellent for those with irregular periods too.)

Does Period Swimwear Work for Other Leaks, Like Light Bladder Leaks?

Yes! Period swimsuits will absorb period blood. But it can also absorb sweat or urine (light bladder leaks.) So if you suffer from urinary incontinence, this is a great product to give you back some freedom and confidence. 

If you do experience light bladder leaks, know you’re not alone. Of the 25 million adult Americans suffering from some form of urinary incontinence, 75-80% of those are women (source.) Pregnancy, childbirth, and menopause are major explanations for the increased prevalence of incontinence in women. However, products like leakproof underwear and leakproof swimwear (aka period swimwear) can definitely make it easier to manage your day-to-day while you explore treatment options.

How Should You Wash Period Swimwear? 

When your period swimwear goes in the laundry with detergent, it releases through the top layer— leaving your swim fresh and clean for tomorrow's laps. Reminder: Don’t use bleach or softener, and lay the bathing suit flat to dry.

2023’s Best Period and Leak Proof Swimwear

Ready to give period swimwear a try. Browse our full selection here. Or, if you’re a teen, you can visit KT by Knix here. Want a little help? Here are some of our top picks.

Best for Classic Style: Leakproof Classic One Piece

This is like a little black dress in swimsuit form. You can’t go wrong with this swimsuit. The Leakproof Classic One Piece has a hidden shelf bra for support, and its clean, classic lines are universally flattering.

How it Fits: 

Smooth fit over the body with medium bum coverage. Fully lined with a no-dig leg opening, built-in inner bra for support, and adjustable straps. Comes in extended sizes that support bigger cups.

Size Options: XS to XXXXL

Best for Gentle Tummy Compression: Leakproof High Rise Bikini Bottom

If you need a little help in the tummy area (who doesn’t, especially at that time of the month?!), the Leakproof High Rise Bikini Bottom is the bikini bottom for you.

How it Fits: 

A banded high-rise bottom with gentle tummy compression, flattering high-rise coverage, plus a built-in absorbent liner for confident period protection. Ultra flattering silhouette is cut moderately on the leg and bum, with a no-dig leg opening.

Size Options: XS to XXXXL

Best for Retro Va-Va-Voom: Leakproof Wrap One Piece

A favorite around our office, it's part bikini & part one-piece! This gorgeous suit features a flattering bikini-style wrap top design PLUS a built-in absorbent liner for confident period protection.

How it Fits: 

The wrap top provides a customizable fit and look. The bottom half sits comfortably with slightly more than medium coverage on the thigh and bum.

Size Options: XS to XXXXL

Shop the full range of period swimwear here

Other FAQs About Swimming on Your Period

Wait: Can You Swim on Your Period?

Absolutely you can! If you’ve been told that swimming during your period is not possible or is unhealthy or unhygienic, you’ve received false information.

Indeed, gentle exercise is great for you while you’re on your period. It may decrease cramps and other menstrual pain, improve your mood, and reduce fatigue. 

Can You Swim Without Period Protection?

There is a bit of a myth out there that period flow stops in the water. This is not true. It may be true for some people that their flow lightens when in water due to the pressure of the water. But a cough, sneeze, laugh, or other exertion, and your flow can gain strength. So, basically, it’s unwise to swim without period protection, though you have options, including:

• Period swimwear
• Menstrual cups
• Tampons

Related: How to swim while on your period

Can You Use a Pad to Absorb Menstrual Blood When Swimming?

You may prefer to use a pad to absorb menstrual blood, but they are NOT meant for use in water. Pads are designed to absorb any liquid they come in touch with, so once they hit the water, they will become saturated quickly. This means they will be swollen and sodden, with no absorption left for blood.

If you bleed, then your blood will have nowhere to go; it will just mix with the water and become diluted. You may even notice a pink trail in the water (depending on how heavy your flow is.) 

Moreover, the adhesive part of the pad will lose its adhesion in water, so the pad may move about or even slip out. And if it’s the kind of pad with ‘wings,’ those will be visible outside your swimsuit.

Key takeaway: Using a menstrual pad in water is ineffective and messy. They’re simply the wrong product for the job.

Are Menstrual Cups a Good Alternative to Tampons When Swimming?

Many of us want alternatives to tampons these days for reasons including:

• Comfort: Some women find tampons uncomfortable to insert and/or wear
• Waste reduction: A person who menstruates throws away roughly 400 pounds of packaging from pads and tampons in their lifetime. (Greater London Authority, 2018)
• Cost: As disposable products, tampons can be prohibitively expensive for some.
• Health concerns: Toxic shock syndrome (TSS) is a rare bacterial infection associated with tampon use. Other reports pose additional questions about the safety of tampon ingredients. 

Menstrual cups are a great alternative to tampons, though it may take some time to find one that’s comfortable for you. However, they are reusable products which means they address many of the concerns people have with tampons.

As we’ve seen, period swimwear is another great alternative and can be used with a menstrual cup, tampon, or on its own. The good news: You have plenty of choices!

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.