How Joanna Griffiths Revolutionized Women’s Underwear With Knix

The period underwear brand is dedicated to celebrating the diversity of women everywhere.
Joanna Griffiths
Joanna Griffiths / Jamie McCarthy/Getty Images

When Joanna Griffiths launched Knix in 2013, she set out to create a brand of leakproof period underwear designed for real bodies and real life. Knowing that 80% of menstruators experience leaks during their period, she saw an opportunity to create an entirely new kind of underwear.

“I really was craving to create a brand that really celebrated women for who they are and that recognized and appreciated that beauty comes in all different shapes and forms, that there’s more than one sort of beauty ideal and that women are more than one thing,” Griffiths says.

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“We ... wanted to celebrate different bodies”

At a time when periods and leaks were still quite a taboo topic, the founder and CEO took a brave risk that certainly paid off. Today, in addition to period underwear, Knix has expanded its line of offerings to include bras, swimwear and activewear. One thing that has remained the same for the intimates brand throughout the years, however, is a dedication to authenticity and inclusion.

“When we launched, we were the first brand to showcase our products on every size we made,” Griffiths explains. “And that was really because we felt like they looked incredible on everyone and really wanted to celebrate the different bodies of people that could wear the products.”

Seven years after Knix launched, the brand created the first lingerie television commercial that exclusively featured women over 50. The campaign was a result of community feedback, in which the public expressed a desire to see older women represented in the company’s advertising.

“Our mission is to empower people to be unapologetically free and we fundamentally believe that for that to happen, we have to feel seen, we have to feel welcome, we have to feel respected and we have to be included,” she adds. “That’s just always been at the forefront of what we’ve done as a brand and have made that a core part of who we are.”

Griffiths bet on herself and her brand, and 11 years in, Knix employs hundreds of people and has established more than a dozen brick-and-mortar retail stores. And even as the company has experienced tremendous growth, the brand’s mission stands strong.

“It’s really beyond anything that I could have possibly imagined,” Griffiths says of her brand’s growth. “I think what’s surprising is how much has stayed the same. How much of what we set out to do when we started in this focus on creating great products that really supported people and creating a brand that made them feel welcome, those two things are still so core to who we are.”

Sarah Nicole Landry
Sarah Nicole Landry in Knix swimwear on the Miami Swim Week runway. / John Parra/Getty Images

“Our community is shaping who we are”

Much of that brand growth can be attributed to customer feedback, which Griffiths and her team take in stride. For example, every day, each Knix retail store shares notes containing customer feedback and opportunities for further evolution.

Additionally, the brand’s swimwear line, which was introduced in 2019, is a result of consumer engagement. While swimwear started with KT by Knix, the brand’s line for teens, the company soon expanded into swimsuit offerings for women, with new styles now available each season. Last year, Knix became the first period swim brand to be featured in the SI Swimsuit Issue, as modeled by Katie Austin in the Dominican Republic. Not only are Knix’s suits fitted on every single size that the brand offers, but Griffiths also incorporates consumer feedback into the mix-and-match designs.

Christen Harper
Christen Harper in Knix swimwear on the Miami Swim Week runway. / John Parra/Getty Images

“You have to have open, two-way communication as a brand,” Griffiths offers. “And we’ve really ensured that our community is shaping who we are. We’ve photographed thousands of people from our community and featured them in our campaigns at this point.”

Ultimately, seeing women confidently strutting their stuff in Knix swimwear has been incredibly fulfilling for Griffiths. She had the opportunity to do just that when SI Swimsuit models Christen Harper, Ellie Thumann and Lauren Chan strutted the Miami Swim Week runway in Knix swimwear, along with content creator Sarah Nicole Landry.

Lauren Chan
Lauren Chan in Knix swimwear on the Miami Swim Week runway. / John Parra/Getty Images

“[We] are capable of more than we we think we are”

Griffiths advises any woman who is dreaming of starting her own business to push through imposter syndrome and “dig deep” to pick yourself up when internal or external doubts begin to creep in.

“For every conversation that you enter and you go into, you mentally have to be grounded in your conviction for the idea, and you have to be prepared to face criticism or feedback that it’s not good enough or you’re not good enough,” she says. “ ... [You need to] remind yourself that just because the person sitting across from you at a boardroom table doesn’t understand what it is that you’re trying to accomplish doesn’t mean that it’s not important and worthwhile of pursuing.”

Additionally, Griffiths says there’s no perfect time to launch a business—you just have to start.

“There’s always going to be a long list of reasons or justifications in your brain as to why it’s not a good time or why you’re not the right person,” she states. “ ... You often don’t know what you’re capable of until you’re put in that moment and I think that all of us are capable of more than we we think we are.”

Cara O’Bleness


Cara is a trending news writer/editor for Sports Illustrated Swimsuit. A passionate writer and editor with more than 10 years of experience in print and online media, she loves storytelling and believes that words have the power to change the world. Prior to joining the team, Cara worked as a writer and editor across a number of content verticals, including food, lifestyle, health and wellness, and small business and entrepreneurship. In her free time, Cara loves reading, spending time with her family and making her way through Michigan’s many microbreweries. She is a graduate of Michigan State University's School of Journalism.