The Bladder Leak Brief - Boxer
S
34.00£
Sale price
34.00£
Regular price
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Made for peri & menopausal women
The bladder leak brief | Your everyday knickers. Without the risk.
Laugh without the fear
Exercise again, without holding back
No smell. No line. Nobody knows.
No more shame. No more hiding.
Feel normal again
Style
Size
SUK 10-12
MUK 14
LUK 16
XLUK 18
2XLUK 20-22
Between two sizes? Go up. Free exchange if it's not right.
How many? Most wear them every day
Try it
Set of 3
See how you get on
£45
£57
£15.00 each
—
The week
Set of 5
Mon to Fri, sorted
£65
£95
£13.00 each
Save £30
The month
Set of 7
One a day, one wash a week
£79
£133
£11.29 each
Save £54
No leaks, no odour, or your money back · 60 days
Free UK delivery · plain packaging, always
Size guide
| Size | UK size | Waist (cm) | Hips (cm) |
|---|---|---|---|
| S | 10 - 12 | 68 - 76 | 92 - 100 |
| M | 14 | 78 - 84 | 102 - 108 |
| L | 16 | 86 - 92 | 110 - 116 |
| XL | 18 | 94 - 100 | 118 - 124 |
| 2XL | 20 - 22 | 102 - 112 | 126 - 136 |
Measure your waist at the narrowest point and your hips at the fullest. Between two sizes? Go up — a brief that digs in will never feel right. Free exchange on your first order if the fit isn't spot on.
No leaks or
it's free, 60 days
No line,
no bulk
Free UK delivery,
plain packaging
Works from the
first day
Description
The Bladder Leak Brief is built for one thing: catching what comes without warning, so you can get on with your day.
You know the moment. A laugh, a sneeze, a cough, and it's happened before you can do anything about it. Pads shift and you never quite know. Period pants are made for blood, thick and slow, so a sudden leak runs off the sides before it's absorbed. You end up wearing two things at once, or wearing black just in case.
Nyth is made for both. The top layer takes a sudden leak in seconds and pulls it away from your skin. The padding runs the full way up, front and back, so nothing escapes when you're sitting down or lying flat. And it looks and feels like ordinary knickers, no line under trousers, no bulk, no sound.
There's nothing to learn. Put them on in the morning and forget about them.
Specifications
Absorbency: designed for a sudden leak, not just a trickle. Absorbs in seconds, holds all day.
Construction: four layers, soft top layer, fast-absorbing core, waterproof barrier, matte outer shell. Padding runs the full length, front to back.
Cut: classic brief, sits below the navel. Bonded edges, no visible line. Wide flat waistband that won't roll or dig in.
Colour: black.
Sizes: S to 2XL (UK 10 to 22).
Care: machine wash cool or hand wash. Hang to dry, roughly 48 hours. No fabric softener.
Why it works
Everything you've tried was designed for one fluid. Your body does two.
Period pants are built around blood: thick, slow, arriving over hours. That's a completely different job from urine, which is thin and arrives all at once. Pour a sudden leak onto a pad designed for a slow flow and it runs off the sides before the core has a chance to take it. That's not you choosing badly. That's the product never having been made for this.
Nyth starts from the other end. The top layer is built for speed, it takes a sudden leak in seconds and moves it away from your skin, into a core that holds it. And because leaks don't always go straight down, the padding runs high at the front for when you're sitting, and all the way up at the back for when you're lying down.
We won't tell you it fixes your bladder. Do your exercises, see your GP, get your treatment, all of that still matters. But none of it works overnight, and you shouldn't have to put your life on hold while you wait. Wear these in the meantime, and get on with it.
Delivery & Guarantee
Free UK delivery on every order, tracked, usually 6 to 12 working days. Plain outer packaging, always, nothing on the parcel says what's inside.
Every pair is covered by our promise: no leaks, no odour, or your money back. Wear them for 60 days. Run in them. Laugh in them. Sleep in them. If they let you down, tell us and we'll refund you in full, and you keep the knickers.
The only thing you're risking is finding out they work.
Important
Nyth is made for bladder leaks, and sold only on this official website. Most leakproof knickers you'll find are period pants — built for a slow flow, not for something that arrives all at once. They look the same, but the padding stops at the gusset and a sudden leak runs off the sides. Those lookalikes aren't Nyth, and they don't come with our free UK delivery, plain packaging or our 60-day no leaks, no odour guarantee. Order here to be sure you get the real thing.
★★★★★
4.8/5 from 2300 reviews
Loved by women who stopped
planning their day around it
★★★★★
Back at my Tuesday class
I'd stopped going two years ago. Ordered these on a whim and went back last week. Nothing happened. That's the whole point — nothing happened.
★★★★★
Nobody would ever know
I wear light trousers now, which I hadn't done in years. No line, nothing showing, and no smell — that was the bit I worried about most. Honestly you'd think they were ordinary knickers.
★★★★★
Honestly, just knickers
I took this to send my sister because she didn't believe me. They look completely ordinary. No bulk, nothing sticking out, and I've had no accidents since.
★★★★★
No more binfuls
I was getting through a packet of pads a week and hating every minute of it. Now I wash them on a Sunday and that's it. Cheaper too, once you work it out.
★★★★★
They don't oversell it
They're clear that this doesn't fix the problem, and I appreciated that. It just means I can carry on while I sort the rest out with my GP. That's all I wanted.
★★★★★
Nothing shows underneath
I wear light trousers to work and I was convinced you'd see the outline. You can't. I checked in the mirror three times the first morning.
★★★★★
Get the seven, honestly
I nearly bought three and I'm glad I didn't. They take a good day or two to dry, so with seven there's always a clean pair. One wash a week and I never think about it.
★★★★★
I feel like myself again
It sounds daft for a pair of knickers, but I'd got small. Cancelling things, staying in, planning everything around the loo. I don't do that now.
Not all leakproof knickers are the same
Most of what you'll find is period pants with a different label. Here's what makes Nyth different, and why it matters when it happens without warning.
Built for speed, not just volume
Period pants are designed around blood: thick, slow, arriving over hours. A leak is the opposite. It's thin and it arrives all at once. Pour that onto a slow-absorbing core and it runs off the sides before anything takes it in. Nyth's top layer is built to take a sudden leak in seconds and pull it straight off your skin.
Padding that runs the full way
On most pairs the padding stops at the gusset, which is fine for a period but useless when you're sitting down or lying flat. Leaks don't always go straight down. Nyth's padding sits high at the front and runs all the way up at the back, so it's caught wherever it goes.
Nobody can tell
Bonded edges instead of stitched elastic, so there's no line under trousers. A wide flat waistband that won't roll or dig in. Matte fabric that makes no sound when you move. And odour control built into the fabric, because that's the part you can't check yourself.
Why it matters when it happens
A laugh, a sneeze, a cough. You don't get a warning, so the product has to be faster than you are.
What most knickers do
✕ Pads shift, and you never quite know
✕ Period pants absorb too slowly for a gush
✕ Padding stops at the gusset
✕ Thick enough to show, and to feel like one
What Nyth does
✓ Takes a sudden leak in seconds
✓ Holds it, front to back
✓ Padding runs the full way up
✓ No line, no bulk, no sound, no smell
A laugh, a sneeze, a cough. Caught before you notice.
You don't get a warning, so the knickers have to be faster than you are. The top layer takes it in seconds and pulls it away from your skin, and the padding runs the full way up — high at the front for when you're sitting, all the way up at the back for when you're lying down. Nothing reaches your clothes. From the very first day.
No period pants in disguise. Made for leaks.
Made for the women menopause turned into strangers. We won't promise to fix your bladder, because nothing you wear can. Do your exercises, see your GP, get your treatment — all of that still matters, and none of it works overnight. What we promise is a pair of knickers that lets you get on with your life in the meantime, instead of putting it on hold.
- Built for a sudden leak, not a slow flow
- Padding runs the full way, front to back
- No line, no bulk, no sound, no smell
Caught In Seconds
A laugh, a sneeze, a cough — it's held before you notice
Nobody Knows
No line, no bulk, no sound, no smell
Full Coverage
The padding runs the full way up, front to back
Just Knickers
Wear them every day and forget they're there
It was never how much. It was how fast.
Every leakproof brand talks about how much it holds. But volume was never the problem. A leak arrives in under a second, and if the fabric can't take it in that fast, it runs off the sides before anything absorbs it. That's why period pants let you down. Speed is the whole idea behind Nyth.
Two fluids, two speeds
Blood is thick and slow, arriving over hours. A bladder leak is thin and arrives all at once. They're not the same job, and a core built for one won't do the other.
Takes it in seconds
The top layer is built for speed. It pulls a sudden leak straight off your skin before it has a chance to spread, then hands it down to the core that holds it.
Covers where it goes
Leaks don't always go straight down. The padding sits high at the front for when you're sitting, and runs all the way up at the back for when you're lying flat.
What happens when it comes
Three things, and all of them before you've noticed.
1
A laugh, a sneeze, a cough. You get no warning at all.
2
The top layer takes it in seconds and pulls it away from your skin.
3
The core locks it away, front to back. Nothing reaches your clothes.
From the first day
Nothing to set up
Put them on in the morning and get on with your day. There's nothing to learn and nothing to remember. Most women stop checking within the first week.
One a day, one wash a week
Never caught short
They take a good 48 hours to dry, so a handful isn't enough. With seven there's always a clean pair, one wash a week, and you never think about it again.
Made for leaks, from the very first day
Day 1
It works from the first morning you put them on
<5s
To take in a sudden leak, before it reaches your clothes
7
One a day, one wash a week. Never caught short
60
Days to try them. No leaks, no odour, or your money back
Frequently Asked Questions
Everything you might be wondering, answered honestly.
No, and this is the whole point. Period pants are built around blood: thick, slow, arriving over hours. A bladder leak is thin and arrives all at once. Pour that onto a slow-absorbing core and it runs off the sides before anything takes it in — which is exactly why so many women find period pants let them down. Nyth's top layer is built for speed, and the padding runs the full way up, front and back, instead of stopping at the gusset.
No, and we'll never pretend otherwise. Nothing you wear can fix your bladder. Do your pelvic floor exercises, see your GP, get your treatment — all of that still matters. But none of it works overnight, and you shouldn't have to put your life on hold while you wait. Nyth is what lets you get on with things in the meantime.
We know this is the one you can't check for yourself, which is why it's the part we take most seriously. The fabric is treated to neutralise odour, and the waterproof barrier stops anything reaching the outside. Wash them properly — cool wash, no fabric softener — and there's nothing to notice. If they do smell, that's covered by the guarantee.
No. The edges are bonded rather than stitched with elastic, so there's no line under trousers. The waistband is wide and flat so it lies against the skin without digging in or rolling down. And the fabric is matte, so there's no sound when you move. Plenty of women tell us they've gone back to wearing light trousers for the first time in years.
Only the absorbent area has extra layers, and it's thin enough that most women forget it's there within a day or two. The rest of the fabric is the same as ordinary knickers. They should feel like underwear, not like protection — if they don't, send them back.
Use the size chart above — measure your waist at the narrowest point and your hips at the fullest. We run from S to 2XL (UK 10 to 22). If you're between two sizes, go up. A brief that digs in will never feel right, and the wrong size is the most common reason these things leak. Free exchange on your first order if the fit isn't spot on.
More than you'd think, and here's why: they take a good 48 hours to dry. Three pairs means washing almost every day. Seven means one for every day of the week, one wash on a Sunday, and you never think about it again. That's why the seven-pack works out cheapest per pair and why most women choose it.
Rinse in cold water, then machine wash cool — or hand wash if you'd rather. Hang to dry. No fabric softener, and no tumble dryer: both coat the fibres and reduce how fast they absorb. Looked after that way, they'll still be working after 50 washes.
Most women don't need to change at all — a pair holds a full day. But if you'd rather have a spare with you, every order comes with a discreet waterproof pouch so you can carry one without anyone knowing what's in it.
No. Every order goes out in plain outer packaging with nothing on it that says what's inside. And your bank statement will only ever show our brand name — never the product.
Free UK delivery on every order, fully tracked, usually 6 to 12 working days. You'll get tracking by email as soon as your order is on its way.
Then you get your money back. Wear them for 60 days. Run in them. Laugh in them. If they leak, if they smell, or if you're simply not convinced, tell us and we'll refund you in full — and you keep the knickers. The only thing you're risking is finding out they work.