NEW!

FLUX Sleep Short™

£32.95
Sleep Short

flow: super heavy

holds 5 regular tampons' worth

Please note: Due to high demand, the following sizes in Black are SOLD OUT and now available on pre-order for dispatch 15th March:


Black - Size S, M, L, 2XL

  • Classic, comfortable cotton
  • Wear all night on a super heavy flow
  • Holds five tampons' worth or 25-30ml
  • For periods, leaks & incontinence 
  • Protective layer from front to back
  • OEKO-Tex certified materials

NEW!

FLUX Sleep Short™

flow: super heavy

holds 5 tampons' worth / 25-30ml

£32.95

Please note: Due to high demand, the following sizes are SOLD OUT and now available on pre-order for dispatch 15th March:


Black - Size S, M, L, XL, 2XL

  • Classic, comfortable cotton 
  • Wear all night on super heavy flow
  • Holds five tampons' worth or 25-30ml
  • For periods, leaks & incontinence 
  • Protection layer from front to back 
  • OEKO-Tex certified materials

Style + fit

Made with quick drying super-soft cotton, bringing you next level comfort. 

Protective layer goes all the way back for extra coverage, making them perfect for sleeping!

Fabric + care

body: 95% cotton 5% elastane 

gusset: 100% cotton, breathable PUL


care: quick rinse 🚿40 degree wash 👌🏽 hang to dry ✌🏿 no bleach or fabric softener ⚠️

Product details
  • Super heavy absorbency - holds up to 5 tampons' worth for up to 12 hours or all night
  • Super-soft and breathable gusset, with our reliable leak-proof technology
  • Soft and comfortable cotton in a boxer short design
  • OEKO-Tex certified materials - safe for your skin

Sustainably sourced

Fast + free UK shipping

Ethically manufactured

We give to girls in need

Better for you. Better for the planet.

*comparison after 3 years use

Period Pants

Disposables


I use 4 pairs


I wash them after use


I spend £1.66 per cycle


I generate 0.2kg of waste

I use 500+ disposables


I throw them after use


I spend £3.74 per cycle


I generate 4.5kg of waste

Customer Reviews

Based on 1 review
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L
L.
Flow: Super Heavy, Heavy
Products used: FLUX Undies, obvs!, Disposable pads
Life Changing

These are amazing! I'm mostly bedbound with Severe M.E so getting my period is an absolute nightmare. I usually use Natracare pads but they always move about and they're so uncomfortable. I have a few pairs of the high waisted flux undies already but they're not enough to get me through a whole day on my first few days and sometimes dig into my groin (I have extremely sensitive skin). But, these are so perfect! I have a suprapubic catheter and these come up high enough to cover it whilst the cotton is lovely on the skin. Thsse are expensive and I've payed with Klarna but they're worth every penny for how much easier my time of the month has become. Thank you so much 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.

  • XXS
  • XS
  • S
  • M
  • L
  • XL
  • 2XL
  • 3XL
  • 4XL

size XXS

UK 4/6   US 0/2   EU 32/34

waist 60-63cm

hips 83-86cm

size XS

UK 8   US 6   EU 36

waist 64-67cm

hips 87-91cm

size S

UK 10   US 6   EU 38

waist 68-72cm

hips 92-96cm

size M

UK 12   US 8  EU 40

waist 73-76cm

hips 97-101cm

size L

UK 14   US 10   EU 42

waist 77-81cm

hips 102-106cm

size XL

UK 16/18   US 12/14   EU 44/46

waist 82-90cm

hips 108-116cm

size 2XL

UK 20/22   US 16/18   EU 48/50

waist 91-101cm

hips 117-127cm

size 3XL

UK 24/26   US 20/22   EU 52/54

waist 102-112cm

hips 128-138cm

size 4XL

UK 28/30   US 24/26   EU 54/56

waist 113-123cm

hips 139-149cm

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 above.

A style to suit you

Meet our other styles

Boyshort

£27.95

flow: heavy

Hi-Waist

£28.95

flow: heavy

Classic Bikini

£27.95

flow: heavy