Tampons haven’t changed in nearly 100 years. 2 women engineers just fixed that.

Tampons have helped women manage their periods for decades. But these feminine hygiene products aren’t perfect. Tampons are prone to leakage, which can ruin your outfit and your day. Even the fear of tampon leaks can be a distraction.

“For many women, potential leaks are in the back of their head when they’re on their period,” Dr. Christine Greves, an ob-gyn at the Winnie Palmer Hospital for Women & Babies in Orlando, Fla., tells Yahoo. “If you’re constantly not able to wear white or having to have people check you to make sure you’re not bleeding out, that’s distracting and disruptive.”

While tampon leaks aren’t a new problem, a duo of female engineers may have found a modern solution. It’s called the Sequel Spiral tampon, and it provides a unique shape that’s designed to tamp down on tampon leaks. Sequel is just starting to get some major buzz, especially in the athletic community. Here’s why, plus how this new design works.

The problem: Leaky tampons are a common issue that many women find distracting and frustrating.

By the numbers: It’s hard to say exactly how many women use tampons, but Harvard’s longitudinal Apple Women’s Health Study finds that these items are the most popular feminine hygiene product used by women. Of the 7,394 women who participated in the study, 47% report using regular tampons, while 33% say they rely on superabsorbent tampons. (By comparison, 46% say they use sanitary napkins or pads, and 16% use a combination of tampons and pads, but not together.)

Unfortunately, leakage is a common problem. One poll found that more than 70% of the women surveyed said they had experienced tampon leakage within the past three months. “A tampon is supposed to prevent you from having to wear a burdensome pad,” Greves says. “But if the tampon doesn’t do the job it’s supposed to do, it does not allow people to comfortably do what they need to do.”

The solution: Enter Sequel. The brand’s spiral-shaped tampon received approval from the Food and Drug Administration in 2023, marking the first major change to a tampon design in nearly a century. “The tampon was originally designed by a man,” Amanda Calabrese, Sequel cofounder and a former elite athlete, tells Yahoo. “We recognized that this was way overdue for a change.”

Alongside cofounder and fellow Stanford University-educated engineer Greta Meyer, Calabrese created the Sequel tampon’s unique helix-shaped design. “When we spoke to people who use period products, we found that tampon leakage was the No. 1 complaint and, after that, it was discomfort,” Calabrese says. “So, we looked at the product from the lens of mechanical engineers.”

Calabrese says that she and Meyer discovered that the traditional tampon design wasn’t as mechanically efficient as it could be. Standard tampons have “vertical channels” that run from top to bottom around the outside of the tampon. “What is not happening is an interruption in the flow path,” she explains. As a result, the standard tampon design opens women up to leaks.

The spiral tampon is designed to interrupt those vertical channels to create more of a horizontal flow, Calabrese says. “That allows the tampon to absorb more evenly than a normal tampon,” she adds.

The Sequel Spiral tampon has the same indications for use as other tampons on the market. Women insert it with an applicator and then should change it at least every six to eight hours, per FDA regulations. (Calabrese says she can’t comment on whether the Sequel tampon needs to be changed less frequently than traditional designs due to guidelines for tampon usage laid out by the FDA.)

Sequel tampons are pricier than traditional tampons, though. The Sequel Spiral tampon is $19.99 for a 32-tampon box at TrySequel.com. By comparison, a 40-pack of regular Tampax tampons is $13.99 on Amazon.

Overall, ob-gyns applaud the concept. “It is possible that a tampon with more surface area and diagonal grooves that spiral downward could lead to better and more even blood absorbency than the current vertical panels seen in traditional tampons,” Dr. Sherry Ross, an ob-gyn in Southern California and author of She-ology: The Definitive Guide to Women’s Intimate Health. Period., tells Yahoo. “This new and innovative tampon design could prove to absorb period blood flow better with more comfort and less leakage.”

Greves calls the design “brilliant,” pointing out that straight lines and gravity are the fastest way to funnel blood out. “Unfortunately, that’s how the traditional tampon is designed,” she says.

But while Greves likes the idea of the Spiral tampon, she says you don’t need to switch if your current tampon is consistently working for you. “If you’ve found your dream tampon, stick with that,” she says. “But if you are struggling with leakage, given that this has passed safety inspections, there’s no harm in trying this new design.”

Ultimately, Calabrese says that Sequel’s mission is to make women’s lives easier. “We want to make sure that you have a product that will stand up to all of the challenges you have throughout your day,” she says. “Reliable options for period products are important.”