Boy Brief

£27.95
Boyshort - Heavy Absorbency

Wear on heavy days

holds 4 tampons' worth

  • Wear for up to 12 hours on heavier days
  • Holds four tampons' worth or 20/25ml
  • For periods, leaks & incontinence 
  • Great for day and night.
  • OEKO-Tex certified materials

Buy more + save more.

Boy Brief

Wear on heavy days

holds 4 tampons' worth / 20-25ml

£27.95

  • Wear for up to 12 hours on heavier days
  • Holds four tampons' worth or 20/25ml
  • For periods, leaks & incontinence 
  • Great for day and night.
  • OEKO-Tex certified materials

Buy more + save more.

Style + fit

Comfort is at the very top of the list with our Boy Briefs.Featuring our classic elastic logo waistband, full of stretch and softness. 


Boy Brief rests at the perfect place keeping you comfortable throughout your cycle. 

Fabric + care

Inner: 95% Modal 5% Elastane, 

Waistband: 100% Polyester, 

Gusset: Absorbent blend, Breathable PUL


Care: Quick rinse 🚿 40 degree wash 👌🏽 Hang to dry ✌🏿 No bleach or fabric softener ⚠️

Sustainably sourced

Fast + free UK shipping

Ethically manufactured

We give to girls in need

Customer Reviews

Based on 69 reviews
88%
(61)
10%
(7)
1%
(1)
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K
K.Y.
Flow: Heavy
Products used: FLUX Undies, obvs!, Menstrual cup
UH-MAZE-ING!

Life changing product... I had been shopping around in zero waste period products and was interested in trying panties, I am SO glad i purchased from FLUX! The first days of my period are very heavy, so I was skeptical about wearing the panties for a whole day, especially when my days last 16 hours sometimes. The panties are a CHAMP! Not even a STRESS of leaking or anything at all! HIGHLY HIGHLY recommend. Will be purchasing again!!!

P
P.
Flow: Moderate
Products used: Disposable pads
Sized very large

I haven't had an opportunity to wear these during period/a run yet, but I ordered my usual size (UK 12) and they were absolutely huge! Probably ok under tracksuit bottoms but would need to.size down for everything else...

N
N.
Flow: Super Heavy
Products used: FLUX Undies, obvs!
Life-changing

Like everyone else, I was skeptical. I'm on the perimenopause rollercoaster, so have very heavy flow at unpredictable times, sometimes flooding too (yay!). I can just put these on and not worry about pads moving to the side when I sit down, and not worry about leaks when I stand up, or if the pad is in the right position if a deluge happens. Not going back, going to buy more pairs. I'm also moved by the increased independence and confidence these products are giving to women (and their carers) who have difficulties with managing periods, particularly those with disablements or learning difficulties. I don't know if FLUX realise how much they have changed things for women. Only drawback is that they're expensive, I hate to think that people on lower incomes might not be able to experience the benefit too.

N
N.
Flow: Heavy
Products used: FLUX Undies, obvs!, Disposable pads
Much More than i bargained for..

I was absolutely shocked by how good these are!! Totally buying more! Absolutely worth the investment!! Thank you Flux!

  • How They Work
  • Money-Back Guarantee
  • Find Your Size
  • FAQ's

Moisture-wicking

Soft material wicks moisture and dries fast

Anti-microbial

Prevents bacteria building up and keeps smells away

Super absorbent

Absorbs liquid without feeling bulky or heavy

Leak-proof

Breathable layer prevents leaks and stains

Moisture-wicking

Soft material draws moisture away and dries fast

Anti-microbial

Prevents bacteria building up and keeps smells away

Super absorbent

Absorbs moisture and liquid without feeling heavy or bulky

Leak-proof

Breathable layer prevents leaks and stains all day

try our period-proof undies risk-free

if you're not period-ing better within 60 days, we'll give you your money back. no questions asked.

what is your return policy?

We offer free returns and exchanges within 60 days of purchase, no questions asked! Just visit our Return & Exchange Centre to get started.

how long can i wear them?

If cared for properly, our undies are likely to have a maximum tech performance of approximately 3 years. This means washing them on a 30-40 degree wash with the rest of your delicates, never using bleach or fabric softener, and hang drying! In terms of length of wear, we measure our undies by absorbency with our highest absorbency styles holding 4 tampons worth of fluid. For some customers, that means wearing them the whole day and for others that may mean carrying an extra pair of FLUX Undies as a backup. 

how do they work?

FLUX Undies are underwear that absorbs your period. Every pair is made with technology that absorbs your flow, wicks moisture, controls odour, and prevents leaks — leaving you fresh and dry. Take a look at our How it Works page to learn more.

how do i find the right size?

We recommend following the hip measurement, as most of our styles sit on the hips. Be sure to measure your hips at their widest point to find the most accurate size for you! In case you don't have a tape measure, you can use the size you usually are most comfortable with for your underwear. We recommend the undies fit snuggly, but not so tight that it's uncomfortable. For reference, you can check out our size chart.