How Does Period Swimwear Work?
Swimming on your period has many benefits, including:
- Exercise lifts your mood and lessens PMS symptoms thanks to a release of endorphins
- Swimming can relieve period cramps (menstrual cramps)
- Exercise reduces the fatigue associated with certain phases of your menstrual cycle
But more than that, there’s no reason you should have to experience FOMO while you’re on your period. While tampons have been a go-to product for many people when swimming, more people want to move away from these products for the following reasons:
- Comfort: Some women find tampons uncomfortable to insert and/or wear
- Waste: Similar to pads (see above))
- Cost: As disposable products, tampons can be prohibitively expensive for some.
- Health concerns: Some people stop using tampons because they are concerned about toxic shock syndrome. Toxic shock syndrome (TSS) is a rare bacterial infection associated with tampon use. Other reports pose additional questions about the safety of tampon ingredients.
The good news: Period swimwear is an all-in-one product that will absorb menstrual blood, protect you from leaks, and also a stylish swimwear option for you to wear poolside, beachside, or lounging in your backyard. But how exactly do period swimsuits work to absorb menstrual blood? Let’s dive in…
How *Exactly* Does Knix Period Swimwear Work?!
Period swimwear (also known as leakproof swimwear or period-proof swimwear) is a relatively new offering. It leverages the same technology as period underwear with some added secret protection to make it work (i.e. absorb menstrual blood) in water.
The best part about leak proof swimwear? Just like period underwear, period swimwear looks just like regular swimwear and comes in a variety of styles, from bikini bottoms to one-pieces. You’ll even have a choice of color!
So how exactly does Knix period swimwear work? The layers in the gusset of the swimwear work to trap and absorb your period 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.
Do I Have to Wear Other Period Protection (Like a Tampon or Menstrual Cup)?
It’s entirely your choice. Some women prefer to double up on protection and pair their period 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 into depending on period swimwear.
However, you don’t need to depend on additional products. If you want to rely fully on your period swimwear, that’s what it’s designed for, and it absorbs menstrual blood on its own. You might want to start wearing it on your light period days to build up your confidence. You can even read a review here to learn about one user’s experience firsthand.
Is Period Proof 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.
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, whether temporary or persistent, 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 reasons for the increased prevalence of incontinence in women compared to men.
Urinary incontinence is a complex topic (there are 5 kinds of urinary incontinence in women), so it’s worth discussing with your doctor. However, products like leakproof underwear and leakproof swimwear (aka period swimwear) can make it easier to manage your day-to-day while you explore treatment options.
Will People Be Able to Tell I’m Wearing Period Proof Swimwear?
Similar to the gusset on leakproof underwear, 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.
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 swimsuits, 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 so much more…
There’s something for everyone. And 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 great for those with irregular periods too.)
Will I Leak Menstrual Blood?
Should you worry about leaving a blood trail in the water if your period products fail? It’s hard to make guarantees here: 50% of us have experienced a period product failing at some point. This is especially common at night.
The big difference is that at night you may have exceeded your product’s absorbency limit. So as long as you choose the right absorbency level for your flow and don’t push those limits, you should be just fine. If you do have a very heavy menstrual flow, you may opt to use another menstrual product (e.g., a tampon or menstrual cup) for additional protection while you swim.
It is worth noting that the water pressure may lighten your blood flow, and even if you do leak a little, it will be quickly diluted in the water, so you’re unlikely to leave the gruesome blood trail that you’re probably picturing in your head.
How Do I Care for My Period Swimwear?
It couldn’t be easier: After your swim, just machine-wash the swimwear on a cold cycle and lay it flat to dry. Do not use bleach or machine dry.
Period Proof Swimwear Cost: Is it Expensive?
Our period swimwear is just slightly more expensive than regular swimwear. But there are immediate savings too: If you replace your disposable products with period swimwear (and period underwear), the initial outlay may be more but you will save money on the monthly purchase of disposable products. You can also feel good about contributing less environmental waste if you ditch disposable products and replace them with reusable products!
The Best Knix Period Swimwear for…
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 in Black
This is like a little black dress in swimsuit form. You can’t go wrong with this swimsuit. The Leakproof Classic One Piece in Black has a hidden shelf bra for support, and its clean and 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, a built-in inner bra for support, and adjustable straps. This swimsuit comes in extended sizes that support bigger cups.
Size Options: XS to XXXXL
Best for Gentle Tummy Compression: Leakproof Ultra High Rise Swim Bottom
If you need a little help in the tummy area (who doesn’t, especially at that time of the month?!), the Leakproof Ultra High Rise Swim Bottom is the bikini bottom for you.
How it Fits:
The perfect combo of comfort and coverage. Designed with an ultra high rise, ruched side seams for subtle gathered look, full butt coverage and premium UPF 50+ fabric. Plus, a built-in absorbent period-proof liner.
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
Written by Jane Flanagan — Updated on April 24, 2023.
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.