The environmental impact of monthly periods can be staggering, due to the amount of waste generated by disposable tampons and pads. How you deal with your period is a deeply personal choice, and here at Treehugger, we respect that for some people, going zero-waste when it comes to periods isn’t the right option for everyone. But if you are looking to use fewer disposable products, there are a number of great alternatives, from menstrual cups to reusable pads, and of course, period underwear.
Tomboy X’s First Line Leakproof Bikini is our Best Overall pick, thanks to top performance it our tests.
Period underwear both looks and feels almost identical to your normal ones but can absorb several tampons’ worth of blood, depending on the style you choose. We put 48 styles of period underwear to the test, evaluating their absorbency against the manufacturer’s claims, as well as assessing the quality of the fabric and the design of the garment.
Below, you’ll find best period underwear, according to our extensive testing.
Tomboy X’s bikini takes the top spot for a range of reasons. Foremost, it absorbed an impressive amount of liquid in our tests, a full 6 teaspoons without leaking or soaking through to the outside. Our testers also like the feel of the cotton body and noted that the absorbent liner wasn’t too thick or stiff. The majority of the garment is cotton, which is what the gynecologists we interviewed recommend. Finally, we think they’re a good value for the price.
Best Overall
TomboyX First Line Leakproof Bikini
In addition to the signature rainbow waistband, there are several other colors to pick from, including an all-black option. This underwear is OEKO-TEX certified, which means the fabric is free from harmful chemicals. The sizing is very inclusive, ranging from 3XS to 6X. The liner is made from a blend of spandex and polyester. You can machine wash them in cold water, but note that they shouldn’t go in the clothes dryer.
We also like that Tomboy X uses fair labor and is a Certified B Corp, which means the brand has made a pledge to put people and planet over profits.
Price at time of publish: $25
This underwear from Cora absorbed 3 teaspoons of liquid easily in our tests, without any leaking, and kept more of a dry feeling than other brands. Like our top pick, it has a mostly cotton body and is OEKO-TEX certified. Our tester liked the feel of the cotton blend, noting that the absorbent layer is not visible but is somewhat firm.
Best Overall Runner-Up
Cora Free-to-Flow Period Underwear
The absorbent layer is made from a blend of polyester and elastane, and reaches fairly high up the back of the garment. They’re only available in black, and come with a mesh laundry bag.
In our tests, EcoPanties absorbed 4 teaspoons of liquid, and still felt less damp feeling on the inside than other undies. They’re our top pick for heavy flows because the absorbent layer covers much of the front of the garment, and in the back reaches all the way up to the back waistband. They’re seamless, which is a less common feature among period panties. They’re available in sizes S to 4X, and in three colors.
Best for Heavy Flows
The Eco Woman Seamless EcoPanties
One potential drawback is that the care instructions ask users to soak the underwear for 30 minutes in cold water prior to hand or machine washing.
Price at time of publish: $22
For those with a light amount of flow or days with just spotting, Saalt’s beautiful period underwear features an absorbent gusset with innovative channels that help distribute liquid and keep you feeling dry. Saalt’s period underwear is made from recycled plastic, each pair is equivalent to about three water bottles worth of plastic. They are certified free of PSAFs, and have third-party certifications from OEKO-TEX and Bluesign, ensuring the undies are free from harmful chemicals.
Best for Light Flows
Saalt Leakproof Mesh Hipster
In our lab tests, these panties didn’t live up to the claims of holding 3 teaspoons of liquid, although they did hold 2 teaspoons quite well. Our real world user liked them both for periods and for postpartum spotting. She found them both comfortable to wear and showed no signs of wear after many washes. We also like Saalt’s lace designs.
The underwear is made in Sri Lanka at a green textile manufacturing facility that uses renewable energy and offers educational opportunities to its workers. The panties are packaged in a recycled paper envelope, to minimize plastic waste while keeping the product clean. Saalt also donates 2% of revenue to charities that help support healthy periods, education, and sustainability.
Price at time of publish: $36
For a prettier panty that can still hold plenty of liquid, Dear Kate’s Ada briefs are a nice choice. They performed extremely well in our lab tests, absorbing an impressive 5 teaspoons without leaking. The lace waist band adds a pretty touch, but it is wide enough to still be comfortable. The underwear is made from a blend of nylon, Lycra, polyester, and elastane (in the lace), and is silky soft to the touch.
Best Style
Dear Kate Ada Full Brief
Sizes range from XS to 3X, and there are several color options to choose from. For every $100 in sales, Dear Kate donates a pair of its underwear to a girl in need.
Price at time of publish: $46
Several of the pairs that performed best in our lab test are made from cotton, including these minimalist ones from Rael. The body of this underwear is 95% cotton, with the addition of spandex. The absorbent pad is also made from 95% cotton, and blended with polyurethane. In our tests, they held 3 teaspoons of liquid, and the outside remained dry. Our testers also noted that the pad isn’t as thick as many other items.
Best Cotton
Rael Reusable Period Undewear
The construction of this underwear feels solid and durable. A mid-range price point (about $20) makes them a good value, and you can also buy a bundle of two or three for a discount. They are only available in black, in sizes from small to x-large.
Price at time of publish: $45
For those who prefer a boxer brief, this pair from Aisle is OEKO-TEX Certified and impressively good at preventing leaks. In our lab, they held 8 teaspoons worth of liquid. The main fabric is a blend of organic cotton, Tencel, and spandex, and the absorbent layer and lining are made from a blend of recycled polyester and organic cotton. You can combine them with a booster for extra absorbency. Sizes range from XXS to 4X, and there are 4 color options.
Best Period Boxer
Aisle Boxer Brief
Aisle first started making reusable period products back in the early 90s, and is B Corp certified, meaning the brand has made a pledge to put people and planet over profits.
Price at time of publish: $48
These shorts are a good option for overnight, and can be worn on their own or under pajama pants. In our lab, they were one of the only garments made from bamboo viscose that performed well, absorbing 6 teaspoons quickly and without any leaks. Our tester was impressed by how slender the pad feels, even when full of liquid.
Best for Sleep
Goat Union Overnight Period Shorts
Only available in black, the sizes range from XXS to 6X.
Price at time of publish: $27
How We Tested
To help inform our testing setup, we first interviewed two gynecologists. We then purchased different styles from a range of popular brands, including Thinx, Modibodi, Bambody, Knix, Pink, Proof, and more.
Period underwear is a great way to cut down on disposable plastic in your life. Our all-around recommendation is Tomboy X’s First Line Leakproof Bikini.
In our lab test, we evaluated 48 period garments, including panties, shorts, and leggings. We measured how much liquid each item could absorb (using dyed vinegar) without leaking, and compared this to the manufacturer’s claims. We also assessed the fabric feel, the garment’s construction, the size and shape of the absorbent lining, and noted if there was any chemical odor on the new product.
After the absorbency test, we washed each pair with unscented detergent to see if any of the vinegar smell remained. None of the tested items retained any lingering scent, so this was not a differentiating factor.
After testing, we assigned each item a star rating from 0 to 5. All the products on this list earned 4.5 stars or more.
What to Consider When Shopping for Period Underwear
Fabric
Both of the doctors we interviewed recommend cotton underwear, however no period underwear on the market is 100% cotton. To create a leakproof barrier, some amount of synthetic fiber is needed, and synthetic materials are also often used in the absorbent pads of these garments.
We also look for OEKO-TEX certification, which indicated that a garment is free from harmful chemicals.
In our tests, bamboo viscose performed particularly poorly (the Goat Union Overnight Shorts were a unique exception), with liquid often rolling off the fabric onto the table or puddling up on top. We think this creates a real risk for leaks, so you’ll want to steer clear of this material.
Absorbency
Absorbency claims vary widely. Some period undies only claim to be “backup” for other menstrual products, while others promise to replace multiple pads or tampons. For this list, we focused on the latter, with items that can be worn confidently without a tampon or menstrual cup. Many brands did not live up to their claims in our tests, but still offered a good level of absorbency.
If you have a heavy flow, you’ll want a product that can hold 3 or more teaspoons. If you have a lighter flow, or for days when you’re just spotting, underwear that holds just 1 teaspoon may do the trick. Some people may find it useful to have a mix of different styles for flows that vary from day to day.
Style
Consider picking period underwear in the same style as the regular underwear that makes you feel most comfortable. If you’re planning on sleeping in your period underwear, you may want a pair where the absorbent pad covers more of the front and back.
Why Trust Treehugger?
Here at Treehugger, we’re dedicated to helping our readers cut waste from their day-to-day lives. We’ve tried dozens of low-waste period products to help you find the best choice for your body and lifestyle.
- How many pairs of period underwear should I buy?
- If you’d like to use period underwear as your primary menstrual product, we recommend keeping at least two pairs per day of flow—one for the day and one for night. A couple of extra pairs on top of that is also handy.
- How do you wash period underwear?
- Generally, period underwear can be machine washed on the cold or delicates cycle, and should be hung up to air dry. Keep in mind that these thicker fabrics may take longer to dry than other kinds of underwear. You may also want to give them a quick rinse in cold water if you’re not washing them right away. Your period underwear should come with care instructions from the manufacturer, it’s best to check for any additional requirements. It’s important to wash period underwear after every use, and before wearing it the first time.
If you’d like to use period underwear as your primary menstrual product, we recommend keeping at least two pairs per day of flow—one for the day and one for night. A couple of extra pairs on top of that is also handy.
Generally, period underwear can be machine washed on the cold or delicates cycle, and should be hung up to air dry. Keep in mind that these thicker fabrics may take longer to dry than other kinds of underwear. You may also want to give them a quick rinse in cold water if you’re not washing them right away.
Treehugger’s Margaret Badore spent a full day in the lab with our test team evaluating period underwear. She also collected insights from real-world users about their experiences with period underwear, and interviewed industry insiders.
