Struggling to find tampons at a store near you? Now might be a good time to give period underwear a try.
The best period underwear can absorb and hold a tampon’s worth of blood — or more. Even better, they are washable and reusable, meaning you create less waste and can save money over time.
Thinx and Dear Kate were two of the first mainstream reusable period underwear brands on the scene, though others were around longer. Now there are many styles and prices to choose from. I tested multiple period underwear brands to find the best ones on the market.
My main criteria in my search for the best period underwear were comfort and absorbency level, but I also judged how bulky each pair was. Unless you’re wearing them only overnight, you’ll want something comfortable, that wears like normal underwear and doesn’t look (or feel) like a diaper. I tested these under tight-fitting pants, like I would any normal underwear, to check for panty lines, bunching and any other signs I was wearing period underwear. Read on for the best period underwear on the market.
James Martin/CNET
Modibodi’s underwear has a lot of things going for it. First, all of the styles are made from natural and/or recycled fabrics, such as bamboo, merino wool and recycled nylon. It’s also designed for both periods and incontinence, so it works for a lot of different needs.
The light to medium absorbency “boyleg” style I tried were incredibly comfortable to the point where I didn’t want to take them off. I thought that the wool gusset would be unpleasant (because wool can be scratchy), but it’s actually really soft. Wool is a smart choice here because it wicks away moisture and keeps you feeling dry. That’s why a lot of socks and base layers are made from it.
Another reason I liked Modibodi is the impressive size range that accommodates waist sizes from 22 to 48 inches — and that’s just the adult sizes. There’s also a teen line of products for smaller bodies.
Modibodi makes more than just period underwear — it also has men’s absorbent underwear to catch bladder leaks and sweat, breastfeeding bras and tops that absorb milk, period swimwear and sleepwear, postpartum underwear and even cloth diapers for babies. The company also has adaptive underwear, designed for anyone with mobility limitations.
If you’re eco-conscious, Modibodi’s new biodegradable period underwear is for you. It’s made from materials that breakdown in soil into nontoxic substances, so you don’t have to feel guilty tossing them when they wear out.
Advertised absorbency:
- Super light: One regular tampon (5ml).
- Light to moderate: Two regular tampons (10ml).
- Moderate-heavy: Two to three regular tampons (15ml).
- Heavy to overnight: Three to four regular tampons (20ml).
- Maxi-24 hours: Up to 10 regular tampons (50ml).
Test results: I tested each pair of underwear on this list to see exactly how much liquid it can hold versus what the company claims. The full details of my methodology are below.
Modibodi absorbed water the slowest of the underwear I tested, however this period product felt the most dry to the touch once it fully absorbed compared to the rest. If you have a light to medium period, you’ll likely feel dry wearing these underwear.
Size range: XXXS to 6XL
Price range: Specifically for the underwear, $18 to $35
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Out of all the underwear I tested, the Dear Kate Nellie Hipster Mini felt the most like regular underwear. That’s a good thing, because no one wants to walk around feeling like they’re wearing a diaper on their period. It’s made from a silky nylon, true to size and isn’t bulky at all.
Dear Kates sells thongs, briefs and hipsters, with some styles available in two different options — mini and regular. The regular style has more coverage than the mini and is better suited for a heavier flow or for wearing for longer stretches of time. The mini style is good for lighter days or when you just don’t need as much coverage.
I liked Modbodi and Dear Kates equally, so choosing between the two was tough. Dear Kates are a bit more slim, so if you need period underwear to wear under your normal wardrobe that has excellent leak protection, get these. If you need more variety of absorbencies (or want to save a few dollars), try Modibodi.
Advertised absorbency: 1.5 regular tampons (around 10ml).
Test results: All period underwear promises no leaks, but the Dear Kates lived up to the claim. It absorbed water very quickly without pooling and didn’t leak past the absorbent fabric into other parts of the underwear. Even when the gusset was fully saturated, the outside of the underwear stayed bone dry. If leaks are a concern for you, these are the period underwear worth getting.
Size range: XS to 3X
Price range: $34 to $46
James Martin/CNET
Thinx underwear is available in five different absorbency levels from lightest (replaces up to one tampon) to super (holds up to five tampon’s worth of fluid). There are several style options to suit anyone’s taste, from full-coverage briefs to thongs. The original styles are made with nylon and a cotton gusset (the extra strip of fabric in the crotch that absorbs liquid), but the company also has an organic cotton line.
Beyond just underwear, Thinx also sells sleep shorts, leotards and workout bottoms that absorb fluid, so you’re covered for any activity.
I’ve owned a pair of Thinx for several years and I’ve been impressed with its quality and performance. My original pair is the Sport style, which I still own and use, and I also got to try the Hiphuggers. Both of those pairs are nylon on the outside so they feel silky and smooth, and the inside is lined with cotton.
Out of all the pairs I tested, Thinx has the most stylish underwear, with little details that make them feel sexy, such as lace waistbands and mesh panels.
Advertised absorbency: Hiphugger style holds up to three regular tampons (15ml), though Thinx advertises 27ml as the max.
Test results: In the water test, the Thinx performed well, but I did encounter some leaks that seeped into the less absorbent parts of the underwear. That said, in real-world testing, I haven’t experienced any leakage, though I did notice the underwear takes awhile to wick away moisture.
Size range: XXS to 4X
Price range: $24 to $42
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In keeping with the trends, American Eagle’s underwear brand Aerie now sells period underwear, though your choices of styles and colors are limited.
If you need period underwear for sleeping, this is your best bet because it has a huge gusset that extends far back to catch any fluids.
If you’re already familiar with Aerie’s boybrief style, this one has the same fit, but it’s bulkier than the other underwear I tested. It was remarkably comfortable and fit well, but because it’s a bit bulky you’ll want to wear it under thicker pants like jeans, or save them for sleeping.
Advertised absorbency: Two regular tampons (10ml).
Test results: This underwear passed the water test with flying colors. It absorbed water quickly with no leaks and didn’t feel soaking wet after. Everything I want in period underwear.
Size range: XXS to XXL
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Aisle underwear sets itself apart from the rest with a removable insert that makes it even more absorbent.
While the insert was a bit tough to get into the gusset and have it lay flat, the underwear felt way less bulky on my body than I expected it to. With the insert, you’re going to have some bunching in the crotch, but the extra absorbency makes it worth it, especially for wearing at night.
Without the insert it still holds about two tampons worth of fluid. The pair I tested had a sport design and was soft thanks to the organic cotton and Tencel — a fabric made from wood that wicks away moisture. This one came in second for the award of underwear I didn’t want to take off.
Advertised absorbency: Bikini style holds two regular tampons (10ml), four tampons with optional absorbency booster (20ml).
Test results: Aisle’s underwear performed well during the water test — it absorbed all of the fluid quickly without leaks. However, it took a while to dry and was still wet to the touch after 30 minutes.
Size range: XS to 5XL
Price range: $32 to $46
James Martin/CNET
Bambody’s absorbent underwear is designed for both periods and postpartum. The full-coverage briefs I tried are made from bamboo, which made them so soft. I highly recommend this style for lounging when you just want to be comfortable, which is not always easy during your period.
This underwear also impressed me on price, with some styles coming in at nearly half the cost of other period underwear I tested without any sacrifice in quality or absorbency.
As a heads up, this bamboo fabric underwear ran small for me, so size up when ordering. Bambody says on its packaging that if you expect to have a heavy flow, you’ll want to use additional “sanitary wear” aka pads, tampons or a menstrual cup. However, you might not need them.
Advertised absorbency: Two regular tampons (10ml).
Test results: Despite the label warning me to use additional protection for a heavy flow, the Bambody briefs were a standout in the water test. They did a great job of absorbing the water right where I poured it, rather than flooding the entire gusset. That means you’ll likely feel much more dry wearing these than the others on this list, especially if you have a heavy flow.
Size range: XXS to 6XL
Price range: $14 to $39
James Martin/CNET
I appreciate that Proof’s underwear is sleek and has flat seams so it doesn’t look conspicuous under your clothes, and that the company sells many different styles to fit your needs.
The Leakproof Full Coverage Hipster style I tested felt comfortable to wear — it’s lined with cotton and uses nylon on the outside. The leak protection was as expected, and performed similarly to the rest of the products I tested.
Advertised absorbency: The Leakproof Full Coverage Hipster holds up to five regular tampons (25ml).
Test results: My original tests gave me inconclusive results, but with additional testing, I found that the underwear quickly absorbed the advertised amount of liquid. One thing to note is that compared to the other options, the gusset of the Proof underwear felt damp to the touch a bit longer than the rest.
Size range: XS to 3XL
Price range: $25 to $43
Knix
Most period underwear can feel frumpy, but Knix is bucking that trend with styles that include slick nylon (with prints!), lace, cotton and modal. I appreciate the variety, which allows you to find a pair that either disappears under your clothes, or provides extra comfort.
On all styles, the gusset is made with Fresh Fix Technology, a layer of absorbent polyester and fabric infused with carbon to help minimize odors. I haven’t had the chance to try this specific feature, but I will update when I do.
Advertised absorbency: Up to 8 teaspoons of liquid (39ml), depending on style.
Testing notes: The leakproof boyshorts I tested absorbed water quickly, without leaking.
Size range: XS to XXXXL
Price range: $23 to $38
What is period underwear?
Period underwear uses layers of absorbent material to collect menstrual blood. If you don’t use tampons or menstrual cups, this underwear can replace sanitary pads and pantyliners. It can also serve as backup protection against leaks from a tampon or cup.
Like regular underwear, it comes in plenty of different styles ranging from thongs to briefs. Most companies also offer levels of absorbency from light to heavy.
Why should I use period underwear?
The main benefit of period underwear is that it cuts down on waste. The average period lasts three to five days and in that time, some folks can easily go through three to four tampons or pads per day — even more period care products if you have a heavy flow and long period. All of those disposable pads and tampons add up over time, costing money and creating waste.
Another benefit of period underwear is that they are typically softer and more comfortable against your skin than disposable pads. And when you’re on your period, being comfortable is really all that matters.
What are the downsides of period underwear?
Period underwear won’t work for everyone. Because of the extra layers of fabric, some period underwear can look bulky under your clothes, especially if they are tight fitting.
There’s also a risk of leaks and stains because the underwear presses up against whatever bottoms you’re wearing and can transfer to them (the same is true with pads). And, despite their best efforts, most period underwear will feel a bit damp or wet as it collects fluid, which can feel uncomfortable.
How I tested
I’m no stranger to period underwear and other “alternative” period products — where my menstrual cup fans at? — so I jumped at the chance to write this guide. When you’re on your period, staying dry and comfortable are the top priorities, so I judged every pair of these underwear through that lens.
I first tested all of the above underwear for fit, to determine if they are true to size. That mostly involved a lot of trying them on, wearing them under pants to see how bulky or slim they were and if you could see panty lines.
Next, I tested the absorbency to see if it lived up to the claims. Since it would take me well over a year to test each one of them while on my period, I developed an easily repeatable method in my home lab (also called the kitchen).
I washed each pair of underwear according to the label and air dried. You’ll want to wash your period underwear before you wear them for the first time to remove any starch or other chemicals used in the manufacturing process. Air drying is important to preserving the underwear’s absorbency — fabric softener or dryer sheets can leave a film behind that doesn’t allow moisture to pass through.
Next, for every pair, I checked how many tampons’ worth of fluid they can hold and converted that amount into millimeters. This is not exact because there’s some variation in tampons across brands, but in general, one regular tampon can hold 5ml of liquid.
I slowly poured that amount of water over the gusset of the underwear to see how quickly it absorbed and if any water leaked. I left them for 30 minutes and then checked to see how dry they were after absorbing the water. Some were just as wet as when I started the test, others were dry enough to comfortably keep wearing.
I will caveat that this is not a perfect test. Menstrual fluid usually leaves your body slowly over the course of a few hours, though some people experience short gushes throughout the day. Some of the underwear I tested didn’t absorb the entire amount of water right away and/or leaked, but that doesn’t mean they wouldn’t work for your period. If your flow is steady over the course of a day, period underwear will have time to absorb it slowly, which will minimize leaks.
If you pass multiple clots during your period or experience repeated gushing/flooding, period underwear might struggle to absorb fluid and keep you feeling dry.
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The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.
