Seamless Thong
Seamless Thong
Seamless Thong
Seamless Thong
Seamless Thong
Seamless Thong

Seamless Thong

Regular price Sale price £16.95
Tax included. Shipping calculated at checkout.

This seamless leak-proof Invisible Thong is perfect for light leaks, sweat, and your lightest days towards the end of your period. Bye-bye pantyliners! Designed with soft, lightweight nylon, they are super stretchy, comfortable and can be worn seamlessly under anything, whilst keeping you leak-free and protected.

The breathable fabric keeps things nice and cool, and of course, our signature built-in tech absorbs moisture and prevents leaks, completely replacing pantyliners and keeping you oh-so-fresh. 🌸

  • For Periods, Leaks and Incontinence

  • Holds Half A Tampon or 1 Pantyliner / 3-5ml

  • 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 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

You may also like...

Why not try some of our best-sellers?

Customer Reviews

Based on 6 reviews
Victoria (Hackney, GB)
Flow: Light
Products used: FLUX Undies, obvs!, Menstrual cup
Great but runs a little small

I love my Flux, they make me feel super comfy and safe when I’m on my period, however I found this style runs quite small and is a bit tight on my hips and tummy (especially with the period bloat..) so I’d recommend going a size up.

Macey Naylor (Mitcham, GB)
Flow: Heavy
Products used: FLUX Undies, obvs!, Tampons

I unfortunately realised I was going to be on my period at prom and so I bought this in replacement of a panty liner that I always wear when I have a tampon in, it was great and I felt secure all night and didn’t have to worry about leaking through my tampon or having a visible knicker line

Little Mouse73 (Newtownabbey, GB)
Flow: Light
Products used: FLUX Undies, obvs!
Little Mouse73

I bought these thongs to wear with my sport gear and jeggings. The are so so comfortable.

Cecília L. (Sant Lluis, ES)
Flow: Heavy, Moderate
Products used: FLUX Undies, obvs!, Menstrual cup

Love them!! so confortable. You can wear whatever you want with them.
I use them with a menstrual cup or for those last days (toward the ends of my period) without anything else.
I bought two of them, maybe I'll need to buy some more!

Roxanne Marshall (Ilford, GB)
Flow: Moderate
Products used: FLUX Undies, obvs!, Menstrual cup
Love them!

So happy to find a thong style period pant! They were so soft but a great cut so still looked great. I used them on spotting days and was really surprised how comfortable they were, they soaked up so quickly so it didn’t feel wet or squishy. Will be buying some more!

Lucy (Luton, GB)
Flow: Light
Products used: FLUX Undies, obvs!, Menstrual cup
Comfy, descrete and effective

I bought these resuable pants to compliment the use of my moon cup and for those days towards the end of my period where I dont need to wear the mooncup but may have some spotting. They are comfy descrete work and feel sexy still.. You dont feel like you are wearing a pad at all. Great buy, would definitely recommend.