Boy Brief

£27.95
Boyshort - Heavy Absorbency

flow: heavy

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.

Boyshort

flow: heavy

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 145 reviews
86%
(125)
10%
(15)
3%
(5)
0%
(0)
0%
(0)
B
B.
Flow: Moderate
Products used: FLUX Undies, obvs!, Cloth pads
Comfortable and effective

Highly recommend! Super comfortable, easy to wash, long lasting. Effortless compared to tampons/towels! Sizing guide was accurate as well.

P
P.E.
Flow: Super Heavy
Products used: FLUX Undies, obvs!
Actually life changing!

I suffer from LS, a painful condition that affects the vulva. Periods cause flair ups which is bad enough, but add pads and every period was beyond agony. I also have the joy of a stupidly heavy flow, so anything less than what looks and feels like an adult nappy will result in enough leakage I may as well camp in the bathroom for a week! I've looked at many brands of period underwear, but most don't hold much or are just for leaks when your already wearing a pad.. not really worth the cost for me. Thank god I found Flux, I got the sleep shorts because I like big knickers that go over my bloated tummy... And they hold 5 tampons worth of blood! They felt a bit bulky when I was holding them, but so comfortable when on, they feel like your just wearing underwear. I wore mine for a whole day and night with zero leaks! No leaks, no dampness, no feeling like I was wearing a soggy nappy. These keep me dryer than anything I've tried before, and I don't react to them like I do pads. So essentially these have changed my life! I'm so happy I nearly cried after my first time using them. Only downside is I cant stop telling everyone about them!

C
C.M.
Flow: Heavy
Products used: FLUX Undies, obvs!
Life changing!* *In a good way...!

I've used STs all my life and have never really thought twice about that. I switched to FLUX because I wanted something more ecofriendly, and it certainly is that - I feel happy never having to buy any more sanitary products again and I can say that these really REALLY work. The boyshorts are great for heavy days and the description on the site really is honest - I've always had heavy periods, but I only need to wear one set through the day, one at night and it's fine. No leaks. No problems. I would recommend getting a set because the one issue is that after you've rinsed these out (easiest in the shower) you then need to put them in the washing machine and leave them to dry without tumble drying, which actually takes a while - about a day on the radiator. This sounds like a slight faff but actually it's pretty straightforward. I would say though that although these aren't cheap, they are definitely worth it. I hadn't appreciate how much better I would feel and how much more free. I would strongly recommend.

N
N.
Flow: Heavy
Products used: FLUX Undies, obvs!, Cloth pads
Great for heavy flow

very comfortable and high absorbency

  • 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.

A style to suit you

Meet our other styles

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Hi-Waist

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Bikini

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