Seamless Bikini

Regular price £21.95
/
Tax included. Shipping calculated at checkout.

These seamless period pants are ultra-thin, super smooth and truly invisible. Bye-bye pantyliners! Designed with soft, lightweight nylon, they are super stretchy, comfortable and can be worn seamlessly under anything.

The breathable fabric keeps things nice and cool, and of course, our signature built-in tech absorbs moisture and prevents leaks, holding up to 2 tampons' worth of blood for up to 8 hours, keeping you oh-so-fresh. 🌸

  • For Periods, Leaks and Incontinence
  • Holds Two Tampons' Worth / 10-15ml
  • Wear For Up To 8 Hours Leak-Free
  • Soft, Stretchy and Comfortable
  • Lightweight and Quick-drying
  • OEKO-Tex Certified Materials
  • Free From Toxins, Chemicals and PFAS/PFOA

Materials: Body95% Nylon 5% Elastane Gusset: 100% Cotton, 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 someone in need. Find out more about our #ByYouForThem giving back scheme here

 

We offer free shipping on all UK orders and free tracked 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. 
 

Delivery options

UK

DPD Next Day Delivery Service 

Next day service, shipped by DPD tracked, £6.95

Royal Mail 1st Class Delivery Service 

1-2 days, shipped by Royal Mail tracked, £4.95

FREE Standard Shipping Service 

2-3 days, shipped by Royal Mail untracked

 

EU

*Free standard shipping is offered on all EU orders above £75 

Express Tracked Shipping Service 

1-2 days, tracked and signed, £14.95

Tracked Shipping Service under £75

3-5 days, tracked, £9.95

FREE Tracked Shipping Service under £75

3-5 days, tracked

 

USA & Canada

*Free standard shipping is offered on all International orders above £75

Express Tracked Shipping Service 

1-3 days, tracked and signed, £19.95

Tracked Shipping Service for orders under £75

5-7 days, tracked, £11.95

FREE Tracked Shipping Service for orders over £75

5-7 days, tracked

 

Rest of world

*Free standard shipping is offered on all International orders above £75

Express Tracked Shipping Service 

1-4 days, tracked and signed, £19.95

Tracked Shipping Service for orders under £75

5-7 days, tracked, £14.95

FREE Tracked Shipping Service for orders over £75

5-7 days, tracked

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

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Customer Reviews

Based on 16 reviews
88%
(14)
6%
(1)
6%
(1)
0%
(0)
0%
(0)
S
Sunny (London, GB)
Flow: Heavy
Products used: FLUX Undies, obvs!, Tampons, Disposable pads
Good

Effective, less to worry about, comfortable, glad I’ve got them.

L
Lucy Wylde (Southampton, GB)
Flow: Moderate
Products used: FLUX Undies, obvs!, Menstrual cup
Such SUCH good pants

I love these so much! They’re so comfy. I feel sexy and comfortable. Truly the best period pants I’ve had. So glad I came across these via my local sustainable shop.

R
Rhi (Stevenage, GB)
Flow: Moderate
Products used: FLUX Undies, obvs!, Menstrual cup
LOVE THEM

I wanted to buy a selection of period underwear from a few different places to try out but after finding these so comfortable I can't see myself going elsewhere. Love the seamless and soft material and perfect fit.

M
Maria R (Frankfurt am Main, DE)
Flow: Moderate
Products used: FLUX Undies, obvs!, Menstrual cup
Amazing feeling, great used together with tampon or cup

Very nice and flatering shape, fits perfectly. The fabric feels great, very soft and ligh. Also very breathable. Easily washable, no stains and no bad odor. Because these are for a lighter flow, I use them together with a menstrual cup. So far, no leakage problems. These are my third pair of FLUX. Compared to other brands I have tried I definitely recomend FLUX undies.
One important thing if you are buying from outside the UK: I had to pay customs taxes to pick them up at the post office.

s
s (Hammersmith, GB)
Flow: Heavy
Products used: FLUX Undies, obvs!, Disposable pads
great fro spotting and light flows

the shape is comfy and nice looking, the padding very thin but absorbant enough for spotting and light flow.
i realy like that they come in several colours (i got the red shade and it looks great kind of raspberry colour).
i use them for lighter days or when i have other type of discharge, but could also see those being useful to go swimming

S
Sarah (Bangor, GB)
Flow: Heavy
Products used: FLUX Undies, obvs!
Great

So soft and comfortable. Much better to wear under tighter clothing than the other types. Would recommend.