FLUX Boyshort

holds 4 tampons' worth

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 rest at the perfect place so you can feel comfortable throughout your whole period. 

Boyshort holds 4 tampons' worth so you can feel covered no matter what your flo'. 

Boyshort - Heavy Absorbency


Holds 4 tampons' worth


Interior: 50% Modal 50% Organic Cotton, Exterior: 82% Nylon 18% Lycra, Trim: 100% Polyester

Please note: Beige Bikini is on pre-order and will be shipped within 1 week



Give 'em a quick rinse 🚿


Chuck 'em in a mesh laundry bag before popping them into the machine on a cold wash 👌🏽


Hang to dry outside or inside! ✌🏿

PS: Don't use bleach or fabric softener ⚠️

Customer Reviews

Based on 62 reviews
Flow: Moderate
Products used: FLUX Undies, obvs!, Menstrual cup
Best period undies ever

I’ve tried 3 different brands of period undies and these are by far the most comfy. Super soft and the boy short provides great coverage with no riding up. I wish I could get these as regular underwear too, I like them that much.

Flow: Super Heavy
Products used: FLUX Undies, obvs!, Disposable pads

My second pair of flux undies and I just love them, so comfy, no leaks and look like normal knickers! I will definitely be buying more!

Flow: Super Heavy
Products used: FLUX Undies, obvs!, Tampons, Disposable pads
Does what it says on the tin

I was apprehensive about trying these at night because who wants to wake up having to strip the sheets/change/shower etc. Surprisingly everything was fine! I'd given myself a little wedgy as to ensure I didn't leak at the top of the pants as the padding only goes part way up and not all the way up like some period pants.

I'm in my 40's and bought some period pants because I'm having issues with tampons. When I tried these on during the day for the first time they do feel like a nappy, they're thick and I'd expect them to be since the absorbancy is for 4 tampons. As I walked out of the house I asked my husband if my the pants made my bum look big. I was told my bum didn't look any bigger than usual (got to have a sense of humour!). The first day is my heaviest so I wanted to test these for at least 8hrs as that's how long I'd be in bed for. This period was particularly heavy and I was experiencing flooding (I tend to use 1 extra super (orange colour) and 1 normal tampon (yellow) on my first 2 days of my period. These pants were fine and I didn't leak at all! I'd washed 1 pair before I went to bed at 22.30 put them on the radiator and they were still wet in the morning at 10.30. I was pleasantly surprised that they were practically dry, they didn't smell at all. I also didn't feel like I'd had cystitis which is why I stopped using towels a long time ago. I only bought 2 pairs to try out. My periods last 3 days so 2 pairs of these for night time wear is fine for me. I've bought others which are much cheaper for day time wear. That's the only downside to Flux, they're VERY expensive at £28 a pair which is why I've knocked off 1 star. But, I bought them specifically for night time wear and they'll serve that purpose. I plan to finish off my tampons etc and plan to use period pants moving forward.

I'm sure I'd be fine using these for a run as I'm run regularly.

All in all, I'm happy I bought Flux.

Flow: Moderate
Products used: FLUX Undies, obvs!, Menstrual cup
Exactly what I was hoping for

Perfect pants - work so well and no requirement for me to use any other products (alongside my Flux pants). Am so happy with these and will recommend.

FLUX Undies are your complete replacement for pads and tampons and can be worn alone for up to 12 hours. 

 Our unique built-in tech is moisture wicking, absorbent, and leak-proof, keeping you covered day 'n' night. 

 Bikini offers full coverage without the bulk, and the soft lace waistband keeps you comfy in style. 

 - Wear all night, or for up to 12 hours during the day 

- Holds 20-25ml, more than any other product out there 

- Our customers use FLUX Bikini for periods, leaks, post-partum, and incontinence! 

- Wear them to school, work, for exercising, or simply just to feel comfortable on lazy days. 

 Find out more on how our undies work.

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