Our sizes can vary product to product! Please check the specific style you want, and measure yourself using the product specific size chart.
Some have a tighter fit for protection, and others are looser to allow for some stretch and movement.
If you have any questions in regards to sizing, please reach out to our friendly team at hi@auntflo.au ❤️🔥
How do the undies work?
AuntFlo period undies work by using a combination of specialised layers designed to absorb, wick away moisture, and protect against leaks. Here’s how these 4 layers of leak-proof protection function together.
1. Absorbent Layer (Closest to Skin)
Function: This layer is designed to absorb menstrual fluid quickly, keeping you dry and comfortable. It pulls moisture away from your skin, preventing any dampness that could cause irritation.
Materials: Made from a blend of cotton, bamboo, and other moisture-wicking fabrics, this layer helps to keep you feeling fresh throughout the day.
2. Moisture-Wicking Layer
Function: This layer moves any moisture absorbed by the first layer away from your body and towards the next layer, ensuring your skin remains dry and comfortable. It also helps prevent leaks by maintaining dryness and comfort.
3. Absorbent Core Layer
Function: This thicker, absorbent core is the key layer for preventing leaks. It’s designed to hold a significant amount of menstrual fluid, often equivalent to 2-3 tampons worth, and is capable of handling moderate to heavy flows without leaking through.
4. Leak-Proof, Waterproof Barrier Layer
Function: The final outer layer acts as a barrier to prevent any absorbed fluid from leaking through to your clothing. This waterproof layer ensures that you stay leak-free while moving, sitting, or sleeping.
How It All Works Together:
The combination of these 4 layers—absorbent, moisture-wicking, absorbent core, and waterproof barrier—ensures that our period undies keep you dry, protected, and comfortable throughout your entire period. They are designed to be worn on their own or as a backup to other menstrual products like tampons or menstrual cups for extra protection, especially on heavier flow days.
Thanks to the leak-proof design, you can wear period underwear with confidence, knowing you are well-protected throughout the day and night, even during activities like walking, sitting, or exercising.
How often do I change my undies?
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:
1. Flow Level
Light Flow: If you have a lighter flow, you may be able to wear your period underwear for up to 8 hours without needing to change, depending on the product's absorbency rating.
Moderate Flow: For moderate flow, you should change your period underwear approximately every 6-8 hours, especially if you feel any dampness or discomfort.
Heavy Flow: On heavy flow days, it's best to change your period underwear every 4-6 hours to prevent leaks. You may need to change more frequently depending on the volume of blood absorbed.
2. Signs of Full Absorbency
Feeling Damp or Wet: If you begin to feel moisture or dampness through your period underwear, it’s a sign that it has reached its absorbency capacity, and you should change them.
Discomfort: If the underwear starts feeling uncomfortable or you're aware of the fabric sticking to your skin, it's a good idea to change them to maintain comfort and hygiene.
3. Personal Comfort
If you start feeling less confident or comfortable, even if the underwear hasn't reached its absorbency limit, it's a good idea to change them. Comfort is key to feeling confident and secure during your period.
4. Activity Level
If you're very active, especially if you're exercising, swimming, or moving around a lot, you might need to change your period underwear more frequently. The increased movement can cause absorption levels to change, and you may feel more comfortable changing to ensure there are no leaks.
5. End of Day / Overnight Use
If you’re using your period underwear overnight, you may want to change them after 8-12 hours, depending on your flow. Consider pairing them with a menstrual cup or tampon for additional protection if you experience a very heavy flow.
Overall, always listen to your body and make changes when you start feeling uncomfortable, to maintain confidence and hygiene.
How do I wash my undies?
Please make sure to regularly wash your undies, and to ensure that you rinse them before machine washing.
For the most hygienic results, we recommend the following washing steps:
1. Pre-rinse using cold water
2. Wash in temperatures under 30°
3. Make sure to stretch them out for the comfiest fit.
4. Hang dry
Yep, it's that easy!
Can these last me all day at work/school?
Yes, period underwear can last the entire work or school day, but it depends on a few factors, such as your flow, the absorbency of the underwear, and your personal comfort.
For lighter to moderate flow, period underwear can comfortably last the entire work or school day.
For heavy flow, you may need to use a backup product or change at least once during the day
Do all undies have the same absorbency?
No they don't! We know not everyone has the same menstrual experience. Here at AuntFlo, each pair of undies are designed for different levels of flows.
Be sure to check out the ratings on each product page (droplets in the top corner).
Is AuntFlo free from PFAs?
Our period undies are PFA free. PFAs are absolutely not part of our AuntFlo product design.
Are you stocked in stores?
Nope, it’s just us! Our AuntFlo underwear are only available on our online store here in Australia (for now).
Where are they made?
AuntFlo is an Australian operated business. However, to create our period undies, we require the machinery and specialised technical skills available in global garment manufacturing hubs, so we have formed partnerships with two fantastic manufacturing partners in China to produce our garments.
Shipping Information
How does delivery work?
Delivery will take between 5-15 days depending on your location.
Once an order is placed, our team will carefully collect your item(s) and package it, so please allow 24 hours and up to 72 hours for our team to pick and pack your order.
We do not dispatch orders on Public Holidays or weekends.
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.
Finally, once we pass your item(s) to our courier, your package is with a different provider. We completely understand delays are frustrating when they occur, however once your order is with the courier, any issues are beyond our control and need to be investigated by our courier. We are able to contact them on your behalf to resolve any issues. Please be assured, we will always do our best to get the issue sorted as quickly as possible for you.
Please note items may ship from multiple locations (including one of our international warehouses) depending on stock availability. We do this to ensure you receive your full order as fast as possible.
How much is shipping?
Country - Australia
FREE Standard Shipping (5-15 Business Days) for orders over $99AUD
Standard Shipping - $9.99 (Orders under $99AUD)
Country - New Zealand
FREE Standard Shipping (5-15 Business Days) for orders over $99NZ
Standard Shipping - $9.99 (Orders under $99NZ)
Country - UK
FREE Standard Shipping (5-15 Business Days) for orders over £50
Standard Shipping - £5 (Orders under £50)
How do I track my order?
Yay, time to celebrate – your undies are on their way! After we pass your order to the courier to be processed, we will send you a shipping confirmation email which will include a tracking number. This can be used to follow your order from AuntFlo HQ to your doorstep!
Haven’t received your shipping confirmation email yet? Check your spam folder too (it may have ended up there).
What if I order the wrong size?
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!
Please note: Change-of-mind and size refunds are not covered under ACCC regulations.
Can I update my address?
Oops, are your undies not being sent to the right address? We will absolutely do our best to change this for you provided you let us know as soon as possible. The sooner you let us know, the more likely it is we will be able to change this over for you.
*Please note: We can only send your order to the address you provide on your order - if you have provided an incorrect address, and the package is delivered there, we are unable to retrieve it so please check your address carefully!
Frequently asked questions
Who do we donate to?
We donate a portion of profits each year to organisations that help women suffering from period poverty. Period poverty refers to the inability to afford and access menstrual products, sanitation and hygiene facilities and education and awareness to manage menstrual health.
This year (2026) we will be donating to Share The Dignity on Christmas Day!
Do you know of an organisation that helps women suffering from period poverty? Please let us know at hi@auntflo.au - we're always looking to partner up with like minded people!
Our Mission
So... you're curious about who is behind AuntFlo? ❤️🔥🩸
After finding out that 1 in 3 women in Australia experience Period Poverty, Ash, a young woman from SA decided to take matters into her own hands. And so, AuntFlo was born and created with women in mind.
After listening to friends, family and eventually customers' feedback, she designed undies that offer women the chance to feel confident and secure in their leak proof undies. AuntFlo has changed the period game.
This young Adelaide woman had a clear goal in mind. Build a like-minded community of women looking out for women. A place to seek period advice, comfy period solutions, and a place to truly make a difference.
Can my undies be rebated?
Yes! In Australia, period underwear, along with other reusable menstrual products like menstrual cups and reusable pads, can be rebated through various local councils. Many councils offer rebates, often 50% of the purchase price, up to a certain maximum amount like $50.
You will need to check with your local council to see if you are eligible for this.
Returns & Exchanges
What is the return policy?
AuntFlo products are labelled as sanitary products, hence, we have strictly implemented a “No Return Policy”.
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.
Please note: Change-of-mind and size refunds are not covered under ACCC regulations.
30 Day Risk-Free Trial
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).
Afterwards, you may:
Keep the remaining items
Donate the unworn pair(s) to charity
Gift them to your bestie
You are not required to return the 1 (one) product you are claiming.
We encourage first time customers to purchase single pairs or small packs before placing a large order.
If you purchase bundles or multi-packs, we encourage you to try one pair first. If you’re not satisfied, we will offer a partial refund equivalent to the cost of 1 (one) pair. You can keep the remaining pairs without any hygiene concerns.
Shipping costs are NOT eligible for credit or refund with our 30 Day Risk-Free Trial for changes of mind - only for products with major faults or defects.
Items excluded from our 30 Day Risk-Free Trial:
Laundry Bags
Bras/Bralettes
Postpartum Bras
To initiate your risk-free trial, please email us at hi@auntflo.au with your order number, the name of the product you'd like to claim, and the reason for your claim.
How long does a refund take to process?
Should you receive a refund for your order, you will receive an email confirming this has been processed from our end. From there, it will take 2-5 business days to process into your account, depending on your bank. If it takes any longer than this, we would recommend contacting your bank or merchant directly.
Are any purchases final sale?
Items marked Final Sale cannot be returned for refund, exchange, or store credit.
Payment Information
How secure is your payment?
Your privacy and security is our highest priority. We use Shopify Payments which is an extremely secure and highly encrypted system designed to protect customers and also hold merchants accountable.
What payment methods can I use?
We accept most methods of payment, such as credit cards (Visa/Mastercard/American Express) as well as debit cards that can be used for online transactions. If you’re a bit more tech-savvy, we offer PayPal and ApplePay too!
How do I apply discount codes?
Woo, it’s on sale - so you’re basically saving money (that's simple girl math... right?!). Simply head to the checkout, and on the first page of the checkout there will be a box for you to enter your discount code in - make sure to click ‘Apply’! This is offered before the payment page so you’re totally aware of how much you can save.
*Please note: Only one discount code can be used per order. If you are purchasing multiple bundles and discounts, we suggest placing separate orders. Strikethrough prices may consider the discount code mentioned in the description. Please check email offers for which items the code is applicable for.
Contact AuntFlo
Something wrong with your order?
Something not quite right with your order? Don’t worry, our AuntFlo team is ready to help you out! Please contact us to advise the issue, and to help resolve things quickly we request you include photos so we can help identify what has happened.
Can I change my order?
These things happen! Please email us immediately with the subject line CHANGE or CANCEL and we will do our absolute best to carry out your request. If it has already been dispatched from our warehouse, you will need to go through our returns process.
As we do our best to get your orders out to you as soon as we can, occasionally an order will be processed before the team has a chance to change it. We cannot guarantee a change of order after the order is placed so please select your items carefully.
How do I contact you?
Emailing us is the way to go!
You can contact us at this address: hi@auntflo.au.
This also allows us to keep a paper trail for your issue so we can help you as best we can. We’re only human, so please be patient as we are working as quickly as possible to get back to you.
We promise we won’t leave you on ‘read’.
Customer Reviews
Overall rating: 4.3 / 5 from 4425 reviews.
Good value and good quality product. I bought the mixed value pack.
The boxer briefs didn’t fit well on me. After many uses there was some leakage from the pink briefs. The seamless briefs and gstring though are unparalleled. The leopard print was unexpectantly great too. They are excellent and I will be repurchasing.
The most comfortable and leak proof period undies ever. I have gone through all the brands and Aunt Flow is by far the best. Low the high waisted G Strings just for every day wear also.
Love, love, love my period undies, so comfortable, wearing them to work with no leaks, wear them to bed and wake up with a clean bed. They make me feel confident and protected.
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 period undies have seriously been a game changer for me! I’ve tried so many over the years, but these are the first ones that make me feel genuinely comfortable, confident AND protected. I’ve now bought nearly every style, from Aunt Flo and the high-waisted Period Gs are my absolute favourite so comfy a flattering! If you’re between sizes, I’d definitely recommend sizing up. 10/10, I’m obsessed! Thank you Aunt Flo!
I look forward to wearing these when I have my period, which sounds crazy. Postpartum baby number 2 my period is ridiculously heavy the first few days and it’s a hot mess. Overnight I now get to be comfortable, not worry about leaking and not feel gross when I wake up! I am about to go place my 3rd order of these!
Since investing in the AuntFlo range of period underwear, I haven't had to stress about my period, what clothing colours or fit of what I wear, any leaks or cost of products.
It's been as easy as putting on normal underwear and going about my day. But better.
Working out at the gym and dealing with sweat, ovulating and dealing with discharge, on my period or having issues because of peri-menopause, I KNOW I'm covered and clean and safe with AuntFlo takes something off my plate that I never wanted there in the first place.
I never knew the weight of it all, until it was lifted.
The one and only time I EVER leaked out of the side (which didn't get my clothes) was when I was sick and in bed for almost 15hours from night3 to day 4 of bleeding. I challenge ANYTHING to keep me anywhere near as comfortable under those circumstances.
I will continually recommend to anyone who has a period. One of the best investments in myself in years!
Comfy full coverage which means no more leak anxiety.. I never thought I'd be so grateful for great period gear, but here we are! Great customer service too - can't recommend highly enough.
These are the best period undies I’ve bought - they are so much more comfortable and secure then other brands I own.
I will be purchasing more!
Love that they come in different colours!
Thank you
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!
Great quality, soft material. Yet to trst how well they work for me but im excited to not have to buy pads anymore. True to size aswell. I would size up if you tend to bloat a lot tough
I have never tried period underwear before and they are truly amazing!! I noticed that I only had cramps for a few minutes the first day when I would normally be in pain the full time!
I bought the best sellers bundle to see which pair was the most comfortable. I was surprised to find the limited edition pink undies was my absolute favourite - I’ve just ordered 5 more pairs. The body and lining are made from a natural fibre, which was the main thing I was looking for. I love how the gusset goes from the front to the back (it’s very reassuring) and they just look so flattering on! Which is so nice when you’re not feeling your best. I actually look forward to my period because I get to wear them 😄❤️
This is my first time trying any sort of period underwear and I’m so in love. These are so comfortable and not bulky. They are perfect and I love that they still look super cute and low rise 💕 I’ve already made another order!!
Loving these period undies.
Probably the best ones I’ve tried. I find them slightly loose around the bum so I will be sizing down on the everyday period undies for my next order.
I’ve never tried period pants before but when I saw the ads I just knew I’d love them. Super comfy and the heavy absorbency is perfect for night time. I never feel dirty wearing them and they’re easy to clean. Just ordered a bundle of another style for during the day. I’d definitely recommend these as a period staple thank you!
I ordered the full flo bundle back in June, and I wanted to try them and review properly for anyone else looking for an honest review!! i haven’t tried them all but will review the rest next month
Classic 2.0
- Really impressed with them! My period started the evening before I wore them, so technically I wore them on day 1.5 which is usually the worst, heaviest time for me. Usually I’d go through 2-3 pads at this time, leaking regardless. I wore them for my full 12 hour shift, no leaks, fully absorbed except for the clots which are never absorbed by pads anyways and came off easily. The feeling of pulling them back up after going to the bathroom wasn’t pleasant, but wasn’t awful either. I rinsed them out while I showered and the blood poured out, it was crazy how much they were able to hold. Really impressed, I will probably buy another few pairs as there are my favourite so far.
Boyfriend Brief 2.0
- Pretty tight around the crotch area and the waist area, not the most comfortable to wear but if you’re skinny it would probably be fine. I have gained a few lbs since I ordered them so i’m not faulting the design.
- They had enough coverage i could wear them around the house and feel like i was just wearing cute skinny shorts honestly
- Again, really impressed with the absorbency, rinsed them in the sink and they were holding far more than i’d thought they were.
Overnight
- Does its job. Comfortable if i little tight around the crotch area, but it stretches and i’m sure will be fine once I’ve worn it a few more times.
- Absorbed a whole nights worth of night 1-2 period with no leaks. Although this is not one of the designs with the absorbent layer from the front seam to the back, which i thought was strange since during the night is the time where I leak the most up top/at the back. (but it worked well so no complaints)
