Classic Bikini

holds OVER 4 tampons' worth

Our bestselling Bikini offers full coverage and protection, keeping you fresh 'n' dry when you need it most. 

Bikini features a soft lace trim that keeps your undies looking so cute, you might even forget you're on your period!

Our bestselling Bikini offers full coverage and protection, keeping you fresh and dry always

Bikini features a soft lace trim that keeps your underwear looking so cute, you might even forget you're on your period!

Our bestselling Bikini offers full coverage and protection, keeping you fresh and dry all the time. 

Bikini features a soft lace trim that keeps your undies looking so cute, you might even forget you're on your period! 

  • Wear For Up To 12 Hours 
  • Holds Up To 25ml, Or 4-5 Tampons' Worth 
  • For Periods, Leaks & Incontinence 
  • For Day & Night

FLUX Bikini


Holds 4-5 tampons' worth, or 20-25ml of blood.

Wear alone for up to 12 hours.


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



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 46 reviews
Flow: Heavy
Products used: FLUX Undies, obvs!, Disposable pads
5 stars

Looking to move on from disposable products so bought a pair of Flux undies. I used them on the first night of my period (which is usually the heaviest) and they were comfortable and no leaks!! I can't wait to buy another pair.

Flow: Light
Products used: FLUX Undies, obvs!, Disposable pads
Magic pants

Go for your standard size for a comfortable fit. I found that the absorbent padding in the knickers was a bit thicker than some other brands (but then that gives you a higher absorbency - decide what you need). Dry all day using one pair and felt cleaner than using a normal sanitary towel. It really does absorb away (faster than a pad I feel) and you feel clean and dry because of it.
I found the padding came up quite high at the back (which I can only assume is for night time for some people, but not something I find I need), but actually felt a bit low at the front for me. I spent all day worrying I would get leakage at the front and pulling my pants forward, while the back larger 2/3 of the pad didn't seem to do a great deal. I didn't get any leaks, but could have done without the worry.
I don't have a heavy flow and these pants did 24 hours for me, no problem. Rinsed out in the sink as soon as I took off, which wasn't as grim and traumatic as I had expected at all. Kept them in a small mesh laundry bag in the bath and washed altogether in the machine at the end of my cycle. Quite an unobtrusive process really. My partner didn't even notice. Did take a few days to dry out fully, but radiators are not on at the moment and it's a bit cooler. I don't need them for a month or so, so no problem! Just be aware if you want them a bit quicker.
The stitching is quite thick around the legs, so you will get VPL. I just wore a skirt or thicker jeans. It's only a couple of days to dress around, but may be an issue for you if you're in a uniform and have no choice. Lace is a nice touch round the top.
I won't be using disposable pads now except for emergencies. I would say I actually prefer these knickers than pads. They feel quite liberating. I got these to reduce my plastic usage, but ended up finding a better period product. Totally converted. A huge success. Really pleased I invested in my magic pants.

Flow: Heavy, Moderate, Light
Products used: FLUX Undies, obvs!

I was looking for period underwear that would completely replace tampons and pads. I kind of rolled the dice with flux and was a bit hesitant at first so I only ordered one regular pair and one light pair, just to try. But these are true game changers. They are honestly SO comfortable and I’m picky with underwear.

In terms of absorption, they are 100% doing the job as advertised. I wore them at day and night and didn’t have leakage. On heavy flow days I wear the regular panties and on lighter days, the light ones. I have now ordered 3 more pairs and would recommend them to anyone! Great product.

Flow: Moderate
Products used: FLUX Undies, obvs!
Great undies but better advice needed

I love these pants. They work, they are comfortable and feel luxurious. However, I have one small quibble; after 3 washes the lace on the waistband started to come away from the pants. I contacted Flux to let them know and they informed me that I should have washed the pants in a small bag to prevent damage when coming into contact with other clothes. Nowhere on the website had this been suggested and I had checked the q&a before washing to ensure that I washed them correctly. I am disappointed that such a quality feeling product has lasted so poorly and that the response was to inform me that this was my fault. Sadly, I think I will be buying my next pair of period pants from another company.

Flow: Moderate
Products used: FLUX Undies, obvs!, Disposable pads

I used these for the first time this cycle and was very impressed. I tried them overnight and during the day. They felt comfortable and I quickly trusted them to do their job.

I did find they took a bit of time to dry after being washed so you would need a fair few pairs. I will continue to use them but the price does mean it needs to be a gradual swap. Worth it in the long run!

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 with no 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, or four tampons' worth 
- Use FLUX for periods, leaks, post-partum, & incontinence!
- Wear them to school, work, exercise, or simply just to feel comfy on lazy days. 

Find out more on how our undies work.

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