TL;DR (Too Long; Didn’t Read 😉): 

Knicked period swimwear and period underwear are both reusable, comfy, and designed to keep you leak-free, but they are designed for different environments. Swimwear works in the water while underwear is made for everyday wear. However, if you want the best of both worlds, our new BFFs hybrid undies are made for every occasion, keeping you protected on land or in water – no change necessary!

The Modern Period Game-Changer

Did you know swimming while you were on your period was once not allowed? Even until recently, sport and swimming was deemed inappropriate during menstruation. This was mostly due to social stigmas and a lack of protective products, but wow does it make us grateful to be living today!

In fact, research today shows that activity, especially swimming, is so beneficial when you’re on your period, helping ease cramps and muscle tension thanks to the endorphins (a.k.a. natural painkillers) and lack of gravity. Aerobic exercises (where oxygen is your main source of energy) like swimming also help alleviate bloating and fatigue, two main symptoms associated with menstruation. 

So what does that mean? Swimming is a game changer for periods! But what to wear during your water time can still be tricky.

Period care has come a long way, from homemade sanitary belts to slim and leakproof options that feel no different from normal underwear. Teens and tweens today especially have it better, with increasingly inclusive products, more menstrual education available, and, should they want it, more discreet options for school, sport, and the beach. 

But, while products are thinner and better than ever, there is still a bit of confusion between period swimwear and period underwear.

Are they interchangeable? (No.) Do you need to wear them at the same time to stay protected while you swim? (No again.) What actually is the difference between period swimwear and period underwear? (You’ll see!)

We answer all this and more below, so keep on reading.

What is Period Underwear?

Period underwear is a more affordable and sustainable alternative to disposable period products. It fits and feels just like regular underwear and can be reused over and over. Just rinse them before popping them into the washing machine with your regular cold load, hang them out to dry and hey presto! They’re good to go again.

You can find out all about how our period underwear works on our ‘How They Work’ page, accessible by clicking here. But to recap, they are made with four layers that work like this:

• Inner layer: moisture-wicking and odour crushing.
• Central layer: locks in the liquid.
• Leak-proof layer: prevents liquid from passing through.

• Outer fabric: either soft eco modal or lightweight cooling/ sweat-proof sports micro-mesh.

These layers work together to create thin, leak-proof undies that will keep you totally protected for up to ten hours without the need of bulky pads or intrusive tampons. 

Oh, and the best part? There are no nasties like PUL's, PFAS or Nano-silver to threaten your health.

Period underwear is perfect for school days, sport training/dance practice, or a cozy sleepover with friends. Generally, if it’s a land-based activity, period underwear has you covered. 

What is Period Swimwear?

Period swimwear, on the other hand, is for anything water-based. Looking and feeling just like your everyday swimwear, period swimwear hasan added layer of waterproof material and StopLeak tech that builds on the leakproof make of our period underwear. This additional layer is essential to keep the period locked in and water locked out, saving wearers from any potential leaks.

Our period swimwear is also anti-pilling, chlorine resistant, SPF50+, AND can be used with white towels without any worry of staining, key factors that also differentiate it from our classic period underwear. 

Again, they contain no nasties and can be reworn again and again.

This product type is the perfect choice for swim squad, school camp, swimming carnivals, the beach, pool, creek, or river, or just lazing around the backyard in summer!

Key Differences Between Period Swimwear and Period Underwear

So, while both period underwear and swimwear are discreet, protective, and comfortable, they are made for two different environments. 

Here’s a summary to keep the differences clear.

Introducing Knicked’s BFFs – The First Hybrid Swimwear/Underwear!

Now, what about if you don’t want to change products between land and sea?

Once, we would have said it’s impossible. But today, we get to say that your wish is our command!

(Allure, update your video. We have a new period product innovation to go down in history.)

Meet our newest product: BFFs - Your Teen’s NewBestieFlowFriend for All Period Emergencies.

BFFs are the world's first 2-in-1:period undies that can be worn both in and out of the water. 

Going from ballet to school to a pool party? No stress. With BFFs you can wear the one period product under your leotard, everyday clothes, and swimmers without hesitation, leaks, or limits.

Of course, we have our signature stop-leak technology, as well as a comfy high-cut and seamless design to ensure you are prepared for any outfit and any activity. The heavy absorbency (with one pair holding up to four super tampons worth of blood!) means fewer outfit changes, less stress, andmore freedom. 

Comfy enough for daily wear AND functional enough for swimming? Count us in immediately.

Oh, and did we mention how cost effective they are? Instead of buying period swimwear, dance underwear, and heavy flow underwear all separately (totalling well over $100 for just one of each), you can spend a third of that - for three times the use!

FAQs / Q&A Section

1. “Can you wear period swimwear as normal underwear?”

   → Usually no, regular period undies are better for daily use, but now with our BFFs product the period swimwear is made to also be normal period underwear!

2. “Can I wear period swimwear without a pad or tampon?”

   → Yes, Knicked swimwear is leak-proof on its own - even for heavy days.

3. “How do you wash period underwear and swimwear?”

   → Cold rinse, gentle wash, no fabric softener, air dry - easy!

4. “How long do they last?”

   → With good care, around 2-3 years.

5. “Can I wear period underwear all day?”

   → Absolutely - they’re designed to stay comfy and dry for hours.

Whether you’re splashing, studying, or sleeping in, we have your flow covered. Check out the new BFFs Hybrid Swimwear & Underwear again here - your all-day, every-day bestie. Or if you’re still trying to find the right period product for you and your lifestyle, click here to check out our whole range.