If you've ever sat on the edge of the pool while everyone else jumped in, you already know the frustration. Whether it's your period, bladder leaks, or just the fear of something going wrong, swimming should never feel like something you have to opt out of.
Period swimwear and leak-proof swimwear have changed the game - but most people still don't understand how they actually work. Do they really hold up in the water? Will anyone notice? Can you genuinely wear one all day?
As the team behind NIXI Body, we've spent years designing period and leak-proof swimwear that actually works and educating girls and women about their options. Here's everything you need to know.
So, How Does Period Swimwear Actually Work?
Let's start with what's happening inside the swimsuit, because this is where the magic is.
Period swimwear isn't just a regular costume with a thicker lining. It's built with multiple layers of specialist fabric, each doing a specific job.
The outer layer is made from waterproof material. This means pool water, sea water - none of it can penetrate the inside of the swimsuit. You're not going to end up waterlogged or uncomfortable.
The inner layers are where the absorbency happens. First, there's a moisture-wicking layer that draws fluid away from your skin so you feel dry. Beneath that sits an absorbent microfibre layer that locks fluid in. And finally, a breathable TPU barrier prevents any blood or urine from reaching the outer layer.
The result? A swimsuit that keeps water out and keeps leaks in without feeling bulky, padded, or like you're wearing a nappy.
What Happens When You're Actually in the Water?
Here's something most people don't realise: when you're submerged in water, the hydrostatic pressure from the water around you naturally slows your period down. So while you're swimming, splashing about, or floating around, your flow is significantly reduced.
The moment you need protection most is when you get out of the water. That's when many women and girls experience a gush as their period resumes its normal flow. This is exactly when the absorbent layers of period swimwear kick in, catching everything before it becomes visible.
This is why period swimwear is such a practical solution. It's not just about being in the pool. It's about walking to the changing room, sitting on a sun lounger, queuing for ice cream - all the moments around the water where leaks are most likely.
How Much Can Period Swimwear Actually Hold?
This is always the first question and it's a fair one.
NIXI Body's swimming costume and bikini both hold up to three tampons' worth of fluid, which is a medium flow absorbency. For most people, that means you can comfortably wear it for a full day at the beach or around the pool without needing to worry.
If you have a heavier flow, you can absolutely still wear period swimwear, just pair it with a tampon or menstrual cup for extra security. Think of it as an additional layer of confidence rather than your only line of defence on heavier days.
It's Not Just About Periods
Here's something the rest of the industry barely talks about: leak-proof swimwear isn't only for periods.
We heard from a woman in her 50s who bought our bikini to take on holiday because she was worried about bladder leaks. She told us it gave her the confidence to sit around the pool with her husband without constantly worrying about damp spots on her sun lounger.
Bladder leaks affect millions of women - after childbirth, during menopause, or simply as part of getting older, yet most leak-proof swimwear brands only talk about periods. At NIXI Body, we think that's a conversation worth widening. If leak-proof swimwear can give someone the confidence to enjoy their holiday, why wouldn't we shout about it?
Real Stories: Why This Matters More Than You Think
We deliver period health education in schools, and the stories we hear remind us exactly why this product exists.
One girl told us that every Sunday her family goes swimming together. It's their thing. But since she started her period, once a month she had to sit on the side and watch. She didn't feel comfortable using tampons, and pads obviously aren't an option in the water. Her mum bought her one of our swimming costumes.
A couple of weeks later, we received an email saying the costume had given her the confidence to get back in the pool. No more sitting out. No more missing family time.
That's what this is really about. It's not just swimwear, it's removing the barriers that stop girls and women from moving their bodies and being part of the moments that matter.
What About Tampons and Menstrual Cups?
Let's be upfront about this: tampons and menstrual cups (preferably organic ones) are great options for swimming. They're internal products that work well in water, and if you're comfortable using them, they're a solid choice.
Period swimwear can work alongside them as an extra layer of security, especially if you're someone who worries about leaks. And for anyone who isn't comfortable with internal products - whether that's a teenager who's just started their period, someone with a medical condition, or simply personal preference, period swimwear gives you an alternative that doesn't require you to insert anything.
For those with heavier flows or conditions like endometriosis or PCOS, where you might be changing a pad every hour, we'd recommend using an internal product combined with period swimwear for the best protection.
"But Will It Actually Work?" Addressing the Scepticism
The biggest concern we hear is simply: will it leak?
It's understandable. The consequences of a leak in a swimming costume feel very public, very visible, and very embarrassing. So the idea of trusting a pair of swimmers to handle your period takes a leap of faith.
Here's what we'd say: the technology is proven. The same TPU barrier and absorbent microfibre layers used in period swimwear are the same technology trusted in period underwear, which millions of women wear daily. The difference is that period swimwear adds a waterproof outer layer to handle submersion.
Start by trying it at home - wear it in the bath, test it out, build your confidence. Once you see that it works, you'll feel far more comfortable wearing it to the pool or beach.
Design That Doesn't Compromise on Style
One of the reasons we created NIXI Body's swimwear the way we did is because everything else on the market looked, well, plain. Generic. Functional but forgettable.
Our bikini features an adjustable tie at the side, which means you can wear it as a high-leg cut or as a short. Feeling bloated? Tie it as a short for more coverage and comfort. Feeling great? Go high-leg. It's one bikini that adapts to how you're feeling on any given day, which, let's be honest, can change hour to hour during your period.
We wanted to create something versatile, comfortable, and appealing to women across different generations. Whether you're 14 or 54, you should be able to find leak-proof swimwear that you actually want to wear - not just swimwear you have to wear.
How to Care for Your Period Swimwear
Looking after period swimwear is straightforward - treat it the same way you would period underwear.
Rinse it in cold water after use to remove any blood or chlorine, then wash it at 30 degrees. Don't tumble dry it, and avoid fabric conditioner - it can coat the absorbent fibres and reduce their effectiveness over time.
In terms of longevity, your period swimwear will last as long as a regular swimming costume. The main thing to be aware of is that prolonged chlorine exposure will affect the lifespan, just as it does with any swimwear. If you're swimming in chlorinated pools multiple times a week, rinse it thoroughly after every use.
Who Is Period Swimwear For?
The short answer: anyone who wants to swim without worrying about leaks.
That includes teenagers who've just started their periods, women who don't want to use internal products, anyone experiencing bladder leaks, athletes who don't want their period to interrupt training, and anyone who simply wants extra peace of mind in the water.
Swimming is one of the best things you can do for your body and your mind. Period swimwear and leak-proof swimwear exist to make sure nothing holds you back from it.
Ready to Try It?
If you've been sitting on the sidelines - literally - it might be time to give period swimwear a go. NIXI Body's swimming costume and 2-way bikini are designed to give you confidence in and out of the water, whether you're dealing with periods, bladder leaks, or just want that extra reassurance.
Because no one should have to miss out on family swims, holiday pools, or beach days because of something as natural as a period.