Bikini style lace period pants
Bikini style lace period pants
Bikini style lace period pants

Bikini - Heavy Flow

Regular price £27.95
Tax included. Shipping calculated at checkout.

Our Classic best-selling Bikini period underwear combines style with function. Holding up to four tampons' worth, they are a dream to wear day and night and can be worn leak-free for up to 12 hours. 

  • For Periods, Leaks and Incontinence
  • Holds Four Tampons' Worth / 20-25ml
  • Wear For Up To 12 Hours Leak-Free
  • Soft, Stretchy and Comfortable
  • Lightweight and Quick-drying
  • OEKO-Tex Certified Materials
  • Free From Toxins, Chemicals and PFAS/PFOA

Materials: Body95% TENCEL Modal 5% Elastane Gusset: Absorbent Blend, Breathable PUL Packaging: 100% Recycled and Recyclable Cardboard

🍃 Bleed Green: Each pair of our period pants replace 200+ disposables from going to landfill, reducing your waste by 99.5%

🤝 Giving Back: For every purchase, we give back to a girl in need. Find out more about our #ByYouForHer giving back scheme here

Please note: Size Large, 2XL & 3XL are SOLD OUT and available on pre-order for shipping 31-July


We offer free shipping on all UK orders and free shipping on International orders over £75.
For same-day dispatch and next day delivery, please place your order before 1pm.
All orders are dispatched from our UK warehouse using trusted couriers such as Royal Mail, DHL and DPD. 
Think our period pants sound too good to be true? Take them on a risk-free trial for 60 days!

If our undies don't work as promised, let us know within 60 days and we'll refund you, no questions asked. The 60-day risk free trial applies to one worn pair of undies only. Refunds will be paid to the original payment method that was used to place the order.
🚿 Rinse after use.
🧽 Machine wash on 30-40 degrees.
 🍃 Hang to dry or dry indoors on a radiator.
⚠️ Do not use fabric softener or bleach. No tumble drying.
And that's it! Your FLUX Undies are ready to wear again!

Our Period Pants Are:

Sustainably Manufactured

We only use eco-friendly materials that are sustainably manufactured

Vegan and Cruelty-Free

Made from natural materials and never with animal materials or testing

Free From Nasties

Certified safe for skin and free from toxins, chemicals and fragrances.

60-Day Money Back Guarantee
How They Work

Our period pants absorb up to 5 tampons' worth of liquid, yet they look and feel just like regular undies.

Our built-in tech works like this:

1. Top layer wicks moisture away from the surface quickly, to keep you dry

2. Our middle layers absorb your blood and lock in your flow

3. The bottom layer pushes liquid back up and keeps you leak-free

It's simple. Just wear, wash and reuse.

Blood, Sweat, Whatever.

Three layers of fabric absorbing liquid showing how period pants work

Customer Reviews

Based on 159 reviews
Flow: Super Heavy, Heavy
Products used: FLUX Undies, obvs!
So Comfortable

I wish these had been in my life for forever! Truely life changing. Much more comfortable than pads and tampons and reducing landfill. Win win! I found them true to size.

Flow: Heavy
Products used: FLUX Undies, obvs!
Great but size up

They are really good quality nice and thick however I would size up as were digging in a little. They keep super dry for hours they are a little expensive and the pad could be bit longer in all honestly but over all good product.

Flow: Moderate
Products used: FLUX Undies, obvs!

Love these, so comfy and absolutely amazing. They look pretty on too!

Flow: Super Heavy
Products used: FLUX Undies, obvs!, Tampons
Comfy and secure

Love the design, noone would know that they were "special". Snug fit gives a feeling of security.

For women with incontinence issues, unfortunately the pants let the urine slosh around and you feel wet for hours, which a normal sanitary pad doesn't do. Next project for Flux should be improving it (or making a similar product) for the thousands of women and mothers (young and older) who have embarassing leakages. PLEASE!

Flow: Heavy
Products used: FLUX Undies, obvs!, Cloth pads, Menstrual cup
Really comfortable

Great product, quite expensive but worth it. Much more comfortable than reusable pads.

Flow: Moderate
Products used: FLUX Undies, obvs!, Disposable pads
Super happy I've tried!

It's really so so much better than using disposable pads. These pants don't feel damp even after 6 or 7 hours and they're very easy to wash. I also find them very comfortable and not tight at all around the legs. They might show a little if you use super skinny jeans, but it's just up to you to not do so for one day if the idea bothers you. I started by ordering one pair of pants and then I ordered more.