Seamless Active Period Undies
✔ Invisible under leggings & activewear
✔ Seamless where it matters
✔ The pair you'll wear on repeat
Ashlee is wearing a size M.
This style runs true to size.
We want you to be as comfortable as possible on your period. Just follow the measurements above.
We recommend measuring yourself, and not going by your standard size. Each style and pair will vary, so please check this if ordering multiple styles.
If you're in-between sizes we recommend sizing up.
Waist: Measure the narrowest part of your waist, below the ribcage and above your hip bone.
Hip: Measure the fullest part of your hip, making sure the tape measure is straight.
Flow: Medium
Absorbency: 20mls
Tampons Equivalent: Up to 3-4 tampons*
Perfect For: Movement & workouts
Feels: Slim and incognito
*(Based on 5ml tampon)
Our Seamless Active Period Undies feel like your most seamless pair, but with a built-in 4-layer leak-proof lining to keep you dry, comfortable, and protected all day. Made with organic cotton to wick moisture and absorb flow, they’re designed to be completely invisible under gym leggings, shorts, and sport uniforms.
Holding up to 4 tampons’ worth, they’re perfect for medium days, comfy, delicate, and made to wear under anything.
Our period undies are also PFA free. PFAs are absolutely not part of our AuntFlo product design.
Care: Pre-rinse, gentle cold machine wash, hang to dry, reuse and repeat. Read our FAQs for more.
OEKO TEX
This product is OEKO-TEX® STANDARD 100 certified and has been tested for harmful substances.
Certificate: 26.HCN.42389
Testing Institute: Hohenstein/HTI
Made From:
Outer: 78% nylon, 22% spandex
Middle: 100% polyester
Inner: 80% polyester, 20% nylon
As per our 30 Day Risk-Free Trial, first time customers can try one garment from your first order risk-free.
You can read more about this here.
These returns rights are in addition to your usual Statutory Rights summarised in this policy. Please read this returns policy carefully as it contains important terms relating to your purchase.
Mix and match colours and sizes of the same style period underwear.
Here's how to claim your free pairs:
🎁 To claim 1 FREE pair: Simply add 3 single pairs to your cart. The offer will be automatically applied to one pair.
🎁 To claim 2 FREE pairs: Simply add 5 single pairs to your cart. The offer will be automatically applied to two pairs.
Please note: This offer can not be combined with other offers or discounts.
Don’t just take our word for it... see how women everywhere are wearing AuntFlo.
Holds up to 3-4 tampons
Perfect for the active girlies
Incognito under your tightest clothes
Better for you & the planet
Uh oh, you've grabbed the wrong size...
Unfortunately, due to AuntFlo products being labelled as Sanitary products, we are not able to switch these over for you. You will need to keep these.
Returned sanitary products cannot be resold, despite claims of them being unused, unworn, and unwashed. This is to maintain and uphold strict hygiene, health, and safety standards to protect our customers and warehouse staff.After all, we’re not only here for the planet, but also for your health!
However, if you are a first time customer with us, we can gift you one pair of underwear (in your correct size) if you have accidentally initially purchased the wrong size.
Please email us at hi@auntflo.au to chat more about this!
Depending on your flow, and the absorbency level of the underwear you have chosen, you can wear our period undies on their own, or with some added protection.
Take some time to figure out what works best for you! Every period is a unique one.
Our period undies are also PFA free. PFAs are absolutely not part of our AuntFlo product design.
Knowing when to change your period underwear depends on a few factors, such as your flow, the absorbency of the underwear, and your personal comfort. Here are some general guidelines to help you determine when it’s time to change:
Overall, always listen to your body and make changes when you start feeling uncomfortable, to maintain confidence and hygiene.
As per our 30 Day Risk-Free Trial, first time customers can try one garment from your first order risk-free. If you're not satisfied with how it functions, we'll gladly refund the cost of that single item (excluding shipping costs).
You can read more about this here.
These returns rights are in addition to your usual Statutory Rights summarised in this policy. Please read this returns policy carefully as it contains important terms relating to your purchase.
Country - Australia
Country - New Zealand
Country - UK
Once your order has been dispatched, we'll send you an email with a tracking number.
If your order hasn't arrived after 15 days please email us immediately and we'll follow up with the courier.
Women from all over Australia, UK & New Zealand are living comfortable and confident!
Overall rating: 4.4 / 5 from 341 reviews.
I have been a period undies wearer for years. Another brand I have always marketed their undies as seamless so I tried them and unfortunately they were definitely not! So when I ordered these I was skeptical but they are amazing. I can wear them at the gym without feeling self conscious and they’re so comfortable. A very happy customer that will definitely be returning!
These were awesome - they go a little higher than I expected but they're pretty comfy. ✨
These are so comfortable and perfect for day to day wear or going to the gym. They fit really nicely. Goodbye to uncomfortable period products I won't ever go back?
Where do I start! They are super comfortable. I have these and the heavy night time ones and I am living life with no regrets! No “did I leak” in the mornings, no annoying pads that ride up your crack. Love them!
These seamlwss period undies are a 10/10, literally threw out all my other period undies for these
These are so comfortable and gives me good support. The fit is perfect, not too firm, not too soft. I pair these with my menstrual disc and it’s perfect.
The most wonderful undies I’ve ever wore 🫶 I will never buy another brand again.
Super comfy and invisible under gym leggings! Love!
Good fit and so comfy and very good
Love the product! Comfortable and reliable!
These are truely the most incredible period undies I’ve tried. I’ve had so many other brands and I do not know why it took me so long to try these. I would have saved so much $$$ I do understand they might looke a bit $$ to begin with but they are on par with all other brands and the bundles once you find your size makes it more affordable!! They are also beyound the quality of any other pairs I’ve ever had!!
So comfy! The right kind of stretch and they stay all day!
Super comfy and fully stocked.
I've tried the undies for 2 cycles now and I'm really happy with them. They sit super comfortable and feel dry throughout the day (even on my heaviest day). I wear them under my leggings and they're pretty much invisible. They truly make my period more comfortable and that's exactly what you need during those days.
Perfect everyday brief!
Comfortable under clothing
Thank you for sending the replacement through! We love it
My biggest gripe with my period old undies was how bulky they were and so I was limited with what I could wear to the gym. These are invisible under my leggings, absorbant and super comfortable. I did buy a bigger size (XL) than I normally am (usually medium) and it fits perfectly.
Feel great for working out, not just for periods but great when lifting heavy with a belt on and accidentally leaking.
The best period undies so soft on. Definitely going to buy more.
Best period undies I have ever tried thank you
recommend sizing up, as I bought in size XL (going by their chart, should be my size, (or possibly a tad small)) and had to size up twice to get the right size. no stress needed tho if you order the wrong size, as with a simple email, you can get a size change free of charge! they are very comfortable to wear, even with a somewhat heavy flow. they honestly feel dry to the touch even after wearing them for 5 hours + good coverage front and back, which is great for me as a back/front sleeper. definitely buying some more pairs now I know my size!!
These are well worth the money!
Love these! So comfortable! Doesn’t even feel like you have period underwear on!
Perfect for under activewear
JUST THE BEST
Absolutely perfect. These saved me on a 5 day hiking trip where I had my period for most of the trip. Absolutely genius product, thank you for existing.
They feel amazing!
Fit my daughter perfectly. She felt supported and in less pain using a tampon. We didn’t get how they worked but they work amazing!!
Great product, runs a bit small
Never used period undies before and now I’m converted. So much more comfortable than wearing a pad, and on heavier days I love the extra protection whilst wearing a tampon.
These are great. Nice and concealed under tights at the gym and super comfy as well.
Really like these grest for under sports wear
Perfect seamless fit under activewear and safe protection against any leaks. Game changing! Would highly recommend to anyone.
Wonderful product for myself and my teenager daughter. Great fit and feel.
They came well packed and are super comfortable! A very happy purchase!
So comfortable to waer don't even feel like you are wearing them not bulky
Generally might take a little getting used to period pads in general but as a starting point using them for sleeping and exercising is a game changer for comfort!
Love love!
Love these.
