Mara S.
and 45.6k+ others across the UK love Isaberry
Cossett™ – Leak-Proof Boyfriend Briefs with Full-Coverage Gusset + 50% OFF
Free shipping with Royal Mail
30-day money-back guarantee
45,600+ happy customers
Only 8 items left for this price
Forget You're On Your Period — All Day, All Night
That background hum of worry every time you stand up, sit down, or roll over in bed — wondering if this is the moment everything leaks through. It steals your focus, your comfort, your confidence.
You've tried period underwear before. Some felt like diapers. Others leaked at the edges. The Cossett™ Boyfriend Briefs are different — built with a gusset that extends from front to back, sealing every angle other brands leave exposed.
This is underwear so comfortable, women say it feels like stealing their boyfriend's favorite pair — soft, stretchy, and completely worry-free.
The full-coverage gusset locks moisture in from every direction while the boy-leg cut sits gently on your thighs with zero dig, zero bulk, zero "period underwear" feeling — just pure, all-day relief.
Why 10,000+ Customers Love Cossett™
✔ STOP CHECKING FOR LEAKS EVERY HOUR - The Cossett™ extended gusset runs from front to back — not just the center like standard period underwear — so you're fully sealed in every position, whether you're sitting at your desk, sleeping on your side, or moving through your day.
✔ NEVER FEEL LIKE YOU'RE WEARING A DIAPER AGAIN - The boyfriend briefs cut uses a stretchy waistband and boy-leg design that sits softly against your skin with zero elastic dig around your thighs. No bulk, no bunching — just underwear you actually forget you're wearing.
✔ ACTUALLY SOFT — NOT "PERIOD UNDERWEAR" SOFT - Made from premium cotton-blend fabric that feels like your coziest loungewear, not stiff clinical material. Soft enough to wear every single day, even when you're not on your period.
✔ FITS EVERY BODY FROM XS TO 4XL — WITHOUT COMPROMISE - Available in 8 sizes with a stretchy, forgiving fit designed for real bodies. Full bottom coverage means no riding up, no awkward adjustments — just pull them on and go.
FAQ
-
Can I wear these on heavy flow days? Yes! The front-to-back extended gusset is specifically designed for heavy flow coverage. For your heaviest days, many customers pair them with a menstrual cup or disc for extra confidence — but on moderate days, they work beautifully on their own.
-
How do I wash them? Simply rinse in cold water after use, then toss them in the washing machine on a cold cycle. Hang dry or tumble dry on low. No special care needed — they're as easy to maintain as your regular underwear.
Specifications
-
Material: Premium cotton-blend with stretchy waistband
-
Sizes: XS – 4XL (8 sizes for inclusive fit)
-
Colors: Grey, Black
Free shipping on all orders - All orders are shipped free of charge.
24/7 customer service - Our customer support team is available daily to answer all your questions.
30-day money-back guarantee - If your experience is not positive for any reason, we will do everything we can to ensure you are 100% satisfied with your purchase.
