A Turn of the Tide

Period underwear offers girls more than a method of managing menstruation.

Collage of period underwear.
Photo illustration by Slate. Photos by Thinx and Happyz.

Read more from Slate’s puberty series. Bonnie J. Rough tells you how to maintain a close and loving relationship with your teen throughout adolescence. Rachelle Hampton assesses the current crop of girl puberty books. Rebecca Onion explains why bra options are so much better for girls today. Nick Greene offers a primer on shaving for first-timers. In case you missed it: Check out Slate’s book list for middle schoolers.

There’s never been a better time to be a menstruating teen. Over the past decade or so, there’s been rapid growth in improved period technologies that allow girls to manage their periods with less fear of being caught with a leaking pad or a backpack overflowing with tampons. Apps like Clue and Flo feature push notifications that adapt to your cycle and alert you when your period’s likely to start. Smaller tampons with pop-out applicators, like Tampax Pocket and U by Kotex Click, fit in tiny pants pockets. (Although—single-use plastic, in this economy?) Menstrual cups—insertable silicone receptacles—by companies like DivaCup, which offers a teen line, and Lena wholly eliminate the need to tote around period supplies. Today’s girls have more menstrual health options than ever, giving them better tools for self-confidence around their periods and greater control over their bodily care.

DivaCup package.

DivaCup Menstrual Cup

DivaCup’s size 0 menstrual cup is made for teenagers.

Perhaps the most significant recent advancement in the teen menstrual landscape is period underwear—leakproof underpants that perform the function of a pad without the visible bulk, tenuous adhesive, plastic waste, or diaperlike feeling. And in the past six years, a mini-boom of retailers—including Thinx, Modibodi, Ruby Love, and Knix—have launched slightly different variations on absorbent undergarments. Now, these companies have started producing lines explicitly for teenagers.

Thinx underwear.

Thinx BTWN Girls Period Underwear

Thinx’s BTWN line of period underwear is explicitly for teenagers.

Period underwear works through a blend of fabric and/or plastic layers that promise varying degrees of moisture-wicking and antimicrobial qualities, breathability, leak resistance, and stretchy comfort. Its technology isn’t all that different from what goes into a disposable diaper, minus the absorbent gel pellets. Each brand of teen period underwear has tried to differentiate itself in the teen marketplace too. Most offer brighter colors and patterns than their more subdued adult lines. Happyz underwear comes emblazoned with a cute little character on the front. BTWN garments are all highly absorbent to accommodate the inconsistency of a girl’s first periods. Knixteen is trying to make itself a content destination for girls with a website that publishes horoscopes and Teen Vogue–esque blog posts, including one that explains how some nonbinary and transmasculine people, not just women, menstruate too.

Happyz underwear.

Happyz Panties for Teen Girls

Happyz appeals to girls by emblazoning the underwear with a cute character.

In many ways, teens and tweens are the ideal market for period underwear. Back in the heyday of teen magazines, readers could scarcely open an issue without confronting at least one terrifying menstrual mishap, from gym class leaks to bloodstains on friends’ parents’ couches to toxic shock syndrome fatalities. Such stories were so ubiquitous that a man who cracked open one of those publications might have surmised that girls spent a good 5 percent of their brain power worrying about periods.


If my recollections are correct, that wouldn’t be too far off. For a young teen or tween who can barely remember to brush her teeth before bed, keeping track of a bout of bleeding that arrives unannounced and requires hour-by-hour vigilance can be tiresome, especially when she has to ask permission to go to the bathroom at school. And in the hyperjudgmental, super self-conscious environs of middle or high school, any visible clue that someone’s on her period—a stain, a dropped tampon—can be grounds for intense humiliation.

Considering the nerves some girls experience over when their periods will first arrive, the unavoidable period product learning curve, awkward parents who don’t want to get all up in their daughters’ business to demonstrate tampon use, and the omnipresent fear (and likelihood) of leaks, young people who menstruate were long overdue for a period product that’s as easy to use as the undergarments they already wear.


Until recently, there had hardly been any period product upgrades since 1969, when companies introduced an adhesive menstrual pad that didn’t need a belt to keep it in place. And even prior to that, advancements were minimal. Around 1920, Kotex began selling pads made of cellulose, an alternative to the rudimentary period underwear of the era: rubber bloomers and aprons with flannel inserts. Modern-style menstrual cups came out in the 1930s, but were unpopular in part because women were too squeamish to come in contact with their own menstrual fluid. Tampons arrived on the scene around the same time, and their applicators, which kept the product at a physical remove, made them a hit.


In spite of the fact that half the world menstruates, the menstrual product industry has gone through long periods of stagnation, in part because of the taboo nature of the need. “It’s hard to sell a product that everybody is too embarrassed to talk about,” Elissa Stein, co-author of Flow: The Cultural Story of Menstruation, told Women’s Health of the commercial failure of early period innovations. It’s also no coincidence that all the companies I’ve mentioned in this article were founded by women. Men are far less likely to be able to spot growth potential and areas for improvement in period technologies, yet men have always made up the vast majority of business leaders and entrepreneurs with access to investment dollars. Ruby Love’s founder, Crystal Etienne, told Racked that she started her company out of frustration that the product she needed—underwear that could firmly keep a pad in place so that it didn’t slide to the side or stick out—didn’t already exist.

Flow book cover.
St. Martin’s Griffin

Flow: The Cultural Story of Menstruation by Elissa Stein and Susan Kim

No aspects of menstruation are off-limits in this cultural history of periods.

In reviews on Knixteen and other teen period underwear websites, parents praise the products for being particularly helpful when their daughters are at school, sports practice, or summer camp, where they may not be able to take regular bathroom breaks to change their pads or tampons. Standard period underwear can absorb between one and two tampons’ worth of menstrual fluid, depending on the style, if worn alone. (Thinx just released a new line of underwear with the absorbency of four regular tampons.) For girls just starting to learn how to deal with menstruation, this kind of flexibility can be a major help—not just as leak prevention, but as mental relief. Siobhan Lonergan, Thinx’s chief brand officer, says the company got more than 1,000 requests from parents for tween and teen period underwear before the brand’s youth line, BTWN, launched in September 2018. Since then, sales have grown 110 percent.


Not everyone believes period underwear is an improvement on existing methods of menstrual hygiene. One blogger found that none of Thinx’s claims to be leak-free, dry-feeling, or odorless held up to her period. Some users might find the products work better as a backup method while wearing a tampon or menstrual cup. And overpreparation for a girl’s first period could make it even more stressful. Ruby Love offers a First Period Kit that comes with period underwear, socks, a bracelet, hair ties—and a few things (hand sanitizer, antibacterial vaginal wipes, disposal bags for pads) that run the risk of making girls feel like their periods are grosser and germier than they really are.

Nonetheless, for many teen users, a method that is neither insertable nor diaperlike is a welcome addition to the period party. It also offers the potential to reduce awkward moments with parents, especially around stains on clothing or bedsheets, and make a teen feel like her period is less of a big, unwieldy, anxiety-inducing deal and more of a normal, manageable fact of life. Whether a girl chooses absorbent undergarments, pads, tampons, menstrual cups, or some combination of these products doesn’t much matter. It’s the widening of the range of available options that stands to better the period experience, by empowering teens to tailor their menstrual routines to their comfort.


More choice in the teen period marketplace has also spawned a refreshing, slow but steady normalizing of conversations about menstruation. This is true in broader society: Thinx made headlines in 2015 for its sexy, visually appealing subway ads; NPR chose a group of middle schoolers’ podcast about menstruation as the winner of its inaugural Student Podcast Challenge. It’s also true on a more personal level: Instead of quietly handing a girl a box of pads and slowly backing away when she gets her first period, parents can present a variety of menstrual care options to their daughters, opening the floor for conversations about sexuality and reassurances that menstruation is a healthy and natural part of growing up.

Now that period product profits have drowned out some of the sexism and squeamishness that curbed innovation in earlier decades, there may be even better forms of menstrual management on the way. The only downside to today’s bevy of products on the market is that they’ve taken so long to get here. As one wistful parent mused in an online review of teen period underwear: “How different our lives would have been had we had this kind of technology way back when.”