Health, Sustainable Fashion, Sustainable Living, Sustainable Product Reviews, Zero Waste

Proof Period Underwear Review: Do Period Undies Work??

Proof Period Underwear Review: Do Period  Undies Work??

I received gifted products from Proof in exchange for posting a photo to social media. This post is not sponsored and is my honest review of Proof.

I’ve been seeing a lot of buzz on social media lately about period underwear. So many influencers claim that their LIVES HAVE BEEN CHANGED by period undies, and I admit, I got pretty curious. I also like that period underwear are a sustainable period solution because they are reusable. So when Proof offered to send me some of their period underwear, I jumped at the chance to try them out and share my findings with y’all! (Proof also gave me a discount code to share with y’all – use code LAURA10 at checkout for 10% off your order.)

About Proof

Proof makes comfortable, absorbent, and attractive period underwear. The underwear essentially functions as a pad would, absorbing your period flow. The underwear can be washed and reused, making them a sustainable period option compared to disposable pads and tampons.

Proof offers many different styles of underwear, from thong to hipster, in varying levels of absorbency. The Proof website helpfully compares the absorbency level of each panty to how many equivalent tampons and/or millileters of flow they can absorb so you can make educated decisions about which style options will work best for your unique situation.

Of note, the company also makes bras that are supposed to help absorb boob sweat!

My Experience Using Proof Period Underwear

Proof sent me two pairs of undies of my choice to try out. I selected the Leak-Resistant Everyday Undie in size medium and the Leakproof Lace Cheeky in size small. I chose black for both because a) I like black and b) it seems like a good color for hiding stains.


I recommend sizing down if you are in between sizes and wondering what to order. I tend to ride the line between small and medium (waist measures small but hips measure medium), and the size small worked best for me. Think about it – you are wanting these undies to be absorbent, so you definitely don’t want there to be opportunity for fluid to leak out because the undies are too loose! Tighter is best.


My next recommendation is to pay attention to how absorbent each panty option is when deciding what to order. The Leak-Resistant Everyday Undie I selected only holds 1 tampon of flow, while the Leakproof Lace Cheeky holds 3 tampons of flow. I was so excited to try these out when they arrived that I put on the Leak-Resistant Everyday Undie during one of my heavier period days – did not end well. Read the absorbency information and act accordingly!


My first impression of the undies is that they are comfortable, cute, and well-made. I was worried they might be thick or feel like you have a giant pad in between your legs, but they essentially feel the same as regular underwear.

Did the underwear actually work?

Okay, the question everyone is wondering: Did the period undies ACTUALLY WORK? Yep, they sure did! They worked just as advertised – the Leak-Resistant Everyday Undie functioned the same as 1 tampon, while the Leakproof Lace Cheeky functioned the same as 3 tampons.

Did I like the underwear, and will I continue to use them?

Did I like them? Yes and no. On my heaviest period days, neither of these pairs will cut it for me. Proof does make a heavier duty panty option, the Leakproof Hipster (equivalent of 5 tampons), and perhaps those would be able to accommodate my heavier flow days. But, I also just don’t love the feeling of period flow not being contained. I have been a die hard menstrual cup user for several years now, and before that I was a tampon user. I’ve never been a pad person and don’t really like the physical sensation of feeling your flow exit your body. My personal preference is to have it contained. So, I think I’ll be sticking with my menstrual cup for heavy to normal period days. However, I can definitely see myself using Proof period undies for lighter days, or as a backup to my cup/tampons if I’m worried about overflow.

Proof Period Underwear Review | Fairly Southern


Several of you sent me questions about the Proof period undies via Instagram, so I want to be sure to answer those!

Are they absorbent? Not soggy and gross?

Yes, they are absorbent! I don’t know how they came up with this crazy cool technology, but they did! They did not feel soggy or gross to me unless they were too full. As long as you have the appropriate absorbency, they feel just fine!

Does it feel like wearing a diaper?

Not at all. This was a concern of mine as well – would they be huge and puffy and uncomfortable? Nope! They feel like regular, silky panties!

Do they smell bad?

Nope, not at all! They don’t smell like anything!

How long can you go wearing them?

This really depends on which pair you select and how heavy your flow is. For me, it’s really not practical to change underwear throughout the day – I want to put on one pair and have it last all day. Because I have heavy periods, this means that neither of these pairs ended up lasting all day for me. Perhaps the super absorbent Leakproof Hipster would. It’s really a matter of matching your flow with the appropriate pair of undie, and then you can theoretically go all day without changing.

Are these made with toxic materials?

According to Proof, all of their undies are successfully tested for PFOA/PFAS, lead, phthalates, and other harmful chemicals. They are Prop 65 compliant. So, they don’t appear to contain materials toxic to humans. However, for those worried about environmental toxicity, it should be noted that Proof uses a variety of materials in their undies depending on the style, including nylon, spandex, cotton, and polyester. Some of these materials are considered not-as-great options for the environment (i.e. polyester) due to shedding fibers into our water supply when washed. Still, when you weigh that against the waste associated with disposable tampons and pads, I think this is probably the more eco-friendly option. My personal opinion is that a menstrual cup would be an environmentally superior option, though.

The Bottom Line

The bottom line? I am impressed with Proof’s period underwear. I’ll still be using my trusty menstrual cup, but I will likely start buying period underwear to use as a backup on heavier flow days and as the primary absorbency method on light days.

I also think these would be a great option for people who are postpartum, experiencing some bladder leakage, or just trying to protect their clothes from everyday discharge or sweat!

Have any of y’all tried Proof underwear, or some other period underwear brand? If so, share your experience with me below in the comments!

xoxo Laura

P.S. – This post contains affiliate links, which means I may receive a small commission (at no cost to you) if you purchase a product using a link from this post. Read more here about my disclaimers/disclosures.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.