It’s as if my entire torso has gone on vacation without me. I don’t know how else to describe the feeling of wearing Numi undershirts—a sweat-wicking, scent-swallowing basic. Imagine period underwear, but for your upper body. Imagine putting half of your body on ice and going off to do other tasks. For those of us who go through the day highly aware of our own sweat, this could change things.

Why do men so often wear undershirts, and women so rarely? Show me a man with a closet full of pristine white Oxfords, and I will show you his stash of Hanes. Women are sweaty too—something I have been telling people, defensively, my whole life. But we’re less likely to wear undershirts, maybe because our clothing is often made of thinner material, or because expectations on women’s bodies hold that we should look as smooth and bulk-free as dolphin.

For some reason, everyday clothes don’t get the same thoughtful design as, say, a pair of high-performance leggings. “It’s crazy when you think about the technology what we demand from our workout clothes,” says Michelle Shemilt, the creator of Numi. “You wouldn’t buy anything for a workout if it didn’t have a technical component or wicking or whatnot, and you wear it how much? The clothes we wear all day—we really need those to work for us, too.”

Shemilt was working in finance when she realized her cute office wardrobe was going to waste. She avoided her delicate silks and knits, fearing a single wear would result in high dry-cleaning bills and potentially ruinous sweat stains. Even those of us who do not trust ourselves to own tops that cost more than $40 are familiar with the pain of taking off a sweater after one wear and knowing that you won’t see it again for an entire laundry cycle. As a result, “I decided to develop a woman’s undershirt that you could really comfortably and practically fit into and wear under women’s clothes, which tend to need a certain design to make it truly invisible,” Shemilt says.

Numi launched in 2014 using the direct-to-consumer model. I’d seen it dozens of times advertised on Instagram, and felt the draw of the seamless, expensive-looking Tencel fabric, the reinforced cotton underarms, and the models, flipping their hair and laughing at the memory of ever having been sweaty. On top of that, the shirts are made with sustainably minded practices in Canada.

Shemilt sent me two of the Signature Numi undershirts—one in almond, one in pink. Both are cute enough to wear as regular tops, tucked into jeans; they’re reversible, so you can wear them with any neckline. If you’re like me and prefer high-waisted jeans that essentially hit one inch below your bra, you could opt for the cropped version.

Whatever activity I did while wearing the Numi—running for the bus, running errands in too many layers, fast-walking while drinking a latte—I didn’t feel that horrible damp warmth that is so often the sad price of life in the human form. 

Numi also recently launched a second radical take on another basic with a stain-repellant, sweat-repellant, machine-washable silk line. “We dove a little deeper and asked, ‘Okay what are other pain points that women have in their wardrobe?’” Shemilt says. “And what kept coming back is that women love wearing silk because you feel nice, you feel elevated—but it is such a finicky fabric that you put it on and you haven’t done anything and all of a sudden there’s a stain out of nowhere. If you have kids, forget about it,” she laughs. (Kelly Ripa’s a fan—she wears the Numi silk button down regularly on her show.)

And when we say stain-repellant, we mean it: Just watch the mesmerizing TikTok of Shemilt pouring coffee and red wine on the crisp silk Numi blouse. With any other silk, seeing it would surely make me sweat…if I wasn’t already wearing the Numi undershirt. 

Jenny Singer is a staff writer for Glamour. You can follow her on Twitter. 

So are consumers done dropping money on it? We are not. A July report from Allied Market Research predicted that the global lingerie market will grow by more than one and a half times by 2028. In the U.S. the lingerie market grew more during the pandemic than in previous years, and is forecast to surpass a value of $10 billion in the next three years.

“There has never been a better time than right now to be interested in intimate apparel and lingerie,” says Harrington. “There have never been more brands, never been more sizes, never been easier access to buying these brands and sizes, never been more price points.”

Harrington, who has made a name as the preeminent lingerie critic of the day, makes the case for valuing lingerie. Investing in undergarments and loungewear, she argues, is not about capitulating to male desire or to a culture of consumption. “We all have certain ways we are expected to look in public,” she says. “For some people it’s a literal uniform like scrubs or a military uniform. Everyone from a bank teller, to a grocery store clerk to a homemaker or even a parent [has this].” The power of intimate apparel, she says, is that it is the one place where the wearer has total freedom. “Because it is hidden, it allows you to express your truest self,” Harrington says. It can be a pure expression of your own identity.

Is your truest self out there, in some configuration of lace, micro-modal, or antigravity tech? If there have been so many changes in the industry, why does bra shopping still feel like running a marathon through quicksand?

The issue, Harrington says, is that the more great options there are, the more consumers have to wade through. “The odds are overwhelmingly in your favor that there is somebody out there making something for you,” she says. “You just probably won’t be able to find it in your local Macy’s.”

Let’s break down the major trends in the new world of lingerie.

Comfort first.

Remember the time before bralettes? A single, damp Band-Aid-looking boob holder could bankrupt you. The rise of the often cuter, more affordable bralette, as well as wireless bras, came in conjunction with a changing beauty standard that deprioritized high, pushed-up breasts. Victoria’s Secret has launched a campaign for its Infinity Flex Bra, which boasts a “gel wire.” Natori, another classic brand, has seen growing online fandom for its Feathers Underwire Contour bra, which is beloved for being comfortable.

VS Bare Infinity Flex Bra

Natori Feathers Underwire Contour Bra

Never Say Never Curvy Sweetie Bralette

Bras are “feats of engineering,” as Lewis puts it. They hold, lift, smooth, contain, sculpt, cradle. Bralettes are simple pieces of fabric—easier to produce and buy. And as athleisure has become not just a trend but a sartorial religion, the bralette’s techier cousin, the sports bra, has also soared. Catering exclusively to small-breasted women is less and less acceptable: Cosabella introduced a luxurious “curvy collection” this summer, and Lewis is partial to the larger models at Evelyn & Bobbie.

Underwear, too, changed. In the early 2010s any number of women you know spent the day with plasticky fibers cleaving to their butt cracks, like medieval hair shirts. The rise of wellness made strong claims for the power of breathable cotton and feather-light bamboo fibers. Turning on a podcast means hearing the word modal repeated hypnotically. 

The American Eagle intimate-wear offshoot Aerie has tripled its market share since 2015, Forbes notes. Hanky Panky, around since the ’70s, is sexy in a way that prioritizes comfort. Harrington has been wearing Chantelle, a legacy lingerie brand, but one that has put out a comfort line, and Knickey, which uses organic cotton. Even La Perla, the ultimate brand for you-give-us-a-thousand-dollars-and-we’ll-give-you-a-fancy-string, put out a comfort collection this summer.

Hanky Panky Women’s Low-Rise Thongs (Five-Pack)

Sex still sells (if men aren’t the only target).

“​​It’s not for his eyes,” says Lewis, articulating what she sees as the prevailing new attitude toward lingerie. “It’s for my eyes. If it happens to appeal the other way, so be it.” Harrington agrees: “The idea that if a partner wouldn’t appreciate it, then you shouldn’t wear it—I reject that. If you like it, then the presence or absence of an audience shouldn’t matter.”

All products featured on Glamour are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.

All products featured on Glamour are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.

All products featured on Glamour are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.

All products featured on Glamour are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.

If you’re reading this Knix period underwear review, you probably know there’s nothing quite like being fast asleep, fully engulfed in sweet slumber, only to be awakened by the floodgates of a heavy period. When I went off birth control during a perpetually single stage in my mid-20s, I became all too familiar with springing awake at 6 a.m. and being met with something akin to an ’80s slasher film once I reached the bathroom. Nature works in mysterious ways, and like clockwork (at the crack of dawn, no less), my uterus would wake up and choose violence—ruining my REM cycle (and my sheets) in the process.

One might think that after 10+ years of having a menstrual cycle surprise stains wouldn’t be an issue, but anyone with a period knows the crimson tide is far from predictable. Practically out of nowhere, my fairly manageable flow decided to throw me a curveball and ramp things up again, triggering flashbacks of super-heavy preteen days when the idea of standing up in class sent me into a panic.

Stained sheets and ruined undergarments are just the tip of the iceberg. Despite what’s on the agenda, misfortunes abound when your flow has other plans, especially if a workout is involved. Few things are as nerve-racking as going into a Down Dog on Day Two of your cycle; the fear of a leak lingers in your mind, no matter how zen the yoga class is. 

I’d known about period underwear since NYC subway stations were plastered with a trendy ad campaign circa 2015, but I never got around to trying them until I was researching for a roundup on the best period panties. Reviewer after reviewer praised the innovative garment for providing a solution to a lifelong problem most women can relate to—so I decided to give them a go.

I was signed up for an outdoor dance cardio class on a hot, mid-summer morning, and it happened to be a particularly heavy day. I decided to try the Knix Leakproof Thong for added protection, and aside from shielding my brand new bike shorts from a hard-to-fix stain, it gave me a newfound peace of mind to focus on movement and stop obsessing over dreaded leakage—with the bonus of having no panty line in sight.

I was immediately hooked. Knix’s absorbent underwear provides backup protection by holding up to one tampon of liquid (or up to six if you go with the Super Leakproof Thong), which is a major game-changer when I’m on the move. And if I’m going to sleep, the Knix Leakproof Bikini Panties (or the Knixy Lace Essential High Rise if I’m feeling cute), are my best friend. I’m finally able to stop rising with the roosters and put my go-to stain remover on sabbatical.

Oh, and if you’re worried about feeling like you’re wearing a diaper, rest assured the seamless, lightweight design is far from it. They honestly feel like regular seamless panties except for the quick-dry, anti-odor gusset, which saves the day when leaks attempt to kill the vibe. Don’t get me wrong—I’m not trying to demonize a perfectly natural bodily function, but I personally am not here for freely bleeding (and neither are my favorite jeans)—so these life-changing undies are here to stay. One of my absolute favorite things about them? They’re totally easy to clean—which I wasn’t expecting at all. The only thing you have to do is wring them out under the faucet then throw them in the wash with the rest of your laundry. Simple as that.  

If you’re ready to see the light, shop some bestselling Knix options below, or if you want more information beyond this Knix underwear review, check out my roundup of the best period underwear for deets on other leading brands in the space.

Knixy Lace Essential High Rise

Knix Leakproof Bikini Panties

Ditch the frilly lingerie she’ll never wear and get her a pack of seamless undies instead. Knix has comfortable styles that are leakproof (up to three teaspoons of liquid) and can be worn everyday, with any outfit—including those only-sheer-when-you-stare black leggings.

Knix Super Leakproof Thong

The elusive dress with pockets. That perfect pair of jeans. When it comes to the most important piece of clothing, panties (or underwear, for those who squirm at the P-word) aren’t usually the first thing that comes to mind. But I’ve always believed that a good outfit requires a good foundation—and if you’ve ever had Bad Panties ruin your day, you know exactly what I mean. Lucky for you and me (and our butts), direct-to-consumer underwear brand Parade just launched the most comfortable seamless panty to hit your top drawer. 

In the past, when it came to our underwear choices, we might have had to sacrifice comfort for style, and vice versa. Thankfully, many modern companies have figured out a way to give us both without compromising, along with more welcoming size ranges—and Parade, which focuses on inclusivity, sustainability, and supporting sexual health organizations, is at the forefront of the comfy-and-cute movement. 

When the New York City–based brand first launched in 2019, I was more than ready for some cool, new underwear to come into my life. Up until that moment, my underwear collection had been restricted to hasty purchases made whenever I was at the mall (remember the mall?) by an unnamed legacy lingerie brand. If I was making better, more mindful choices with the rest of my clothing, why not extend that to my underwear drawer? Plus, they speak to my personal interests. One of Parade’s collections is based on astrological signs, while another featured a collaboration with the aughts It brand Juicy Couture. As someone with multiple velour tracksuits, this was an absolute dream come true.

The brand’s latest release, Universal, is not a collab or inspired by a trendy theme, however. Instead, it addresses a common complaint: panty lines, as well as a more (actually) universal issue, climate change. 

Universal is the brand’s first-ever invisible style, so you can kiss those dreaded panty lines goodbye (unless you’re like me and don’t mind a panty line!). But what makes this seamless underwear stand out from the rest is what it’s made of: supersoft recycled fabric and organic cotton lining. According to Parade’s founder and CEO, Cami Tellez, Universal is made from certified recycled yarns that result in 8.5% energy savings, 84% wastewater savings, and 77% less gas generation savings. “Sustainability is at the core of our brand,” says Tellez, “so on top of launching the world’s first carbon-neutral edgeless underwear, we took our efforts a step forward by investing in the conservation of May Ranch—over 14,500 acres of native prairie land in Colorado, and a vital home to over 300 bird species. This project will dramatically improve air quality in a state that has lost 48% of its natural grasslands in recent years.” 

Whether you are tired of ruining your bedding, are dealing with unpredictable spotting, or just want added protection, the best period underwear could be the solution you’re looking for. With a range of absorbent underwear on the market, there’s a number of factors to consider before choosing the right style for you, from the heaviness of your flow to your plans for the day (or night). 

When shopping for something so personal, testimonials from happy customers can offer added trust in the product’s efficacy, so we did a deep dive to find out which period underwear is worth writing home about. These are the period panties women are logging on to sing the praises of—the undies that changed their lives for the better, from comfy, size-inclusive briefs to barely there thongs. 

Before you shop for the best period underwear, there are some things you should know about wearing them. Read up on the information to know now, from an ob-gyn and period underwear manufacturers, ahead.

How period underwear works

In essence, period undies work the same way as regular underwear does—but with the added absorption setting them apart. Expertly designed menstrual underwear shouldn’t feel different to the touch or on the body, but they should include an added layer of fabric that can either work in lieu of a pad or tampon or provide extra protection to avoid leakage. 

“Just like each woman, period underwear types are unique and serve different purposes,” says ob-gyn and pH-D Feminine Health adviser Ruth Arumala, D.O. “Some create an extra barrier of protection from leakage; others take the place of other feminine hygiene products.” Different brands use various patented technology to ensure optimal absorption, and every company in this roundup is backed by real women who swear by the products.

How to use period underwear 

First step: Put them on. Second step: Breathe easy and forget about ’em. But in all seriousness, the most important factor of period underwear is convenience, and how you choose to use them will depend on your personal needs and preferences. While some women seek added protection to avoid disaster stains during busy days when their menstrual flow is extra heavy, others are looking for worry-free REM cycles and workouts, and period undies can help provide peace of mind (even if you choose to wear a tampon with them).

How to wash period underwear

The first thing to do once you take off your period underwear (never wear them for more than 24 hours) is run them under cold water until the water runs clear. Once most of the blood is removed from the gusset, you can throw them in with a regular load of laundry on a delicate, cold-wash cycle (be sure not to use hot water to avoid setting any remaining blood into the underwear). You can also put them in a delicates bag to keep them extra safe in the washer. Due to the high-tech nature of the fabric, you’ll want to hang-dry rather than tumble. Once the underwear is nice and dry, fold them up and bring them out on your next moon cycle.

Can period underwear replace pads?

Every body and flow is different, but the short answer is yes, period underwear can replace pads. Because of technology used to develop fabric that can hold multiple tampons’ worth of blood, it’s generally not recommended to wear pads with your absorbent undies. Experts at Modibodi, Thinx, and Knix agree you can nix pads altogether. Arumala cosigned this point, explaining it’s more common to pair period panties with tampons or menstrual cups. “Most period-panty users either wear them solo or use tampons or cups,” she says. “It is rare to use pads or panty liners with period panties.” 

Benefits of using period underwear 

From keeping your clothes clean to going easier on the environment and saving money, there’s a wide array of benefits to using period underwear. Knix founder Joanna Griffiths dished on a few key benefits: She says period panties “take away the worry of not knowing exactly when you might get your period throughout the day and remove the need to carry panty liners, pads, and tampons”; “positively impact our environment”; and “revolutionize menstruation worldwide, especially for those who may not have access to, or cannot afford, expensive disposable products.” Arumala adds that they’re useful for “preventing vulvar and/or vaginal irritation, as well as when culture or religion reasons preclude use of internal products.”

Where to buy period underwear

Now that we’ve covered the most common questions surrounding period underwear, it’s time to shop! Ahead, the 16 best period panties online reviewers can’t imagine their life without—and that’s on period.

All products featured on Glamour are independently selected by our editors. However, when you buy something through our retail links, we may earn an affiliate commission.