The importance of creating period products for every body

Why there’s no such thing as ‘one size fits all’

It might seem like an obvious statement—but if we look at the way most period products are made, we’ll see that it’s often forgotten:

Vaginas are like snowflakes. No two are exactly alike. Likewise, everyone has a different period in terms of heaviness, length, and even consistency.

If you’ve ever tried a period product that wouldn’t function properly (whether it was uncomfortable to wear, leaking, or even downright impossible to insert), you might have assumed that there was something wrong with your technique. Or, perhaps, that there was something wrong with the product itself.

But there’s a third scenario to keep in mind: The product just isn’t compatible with your anatomy.

Maybe you have a retroverted uterus. Maybe you have a low cervix—or a particularly high cervix. It could be that your pubic bone extends further down than the “average” person’s. Or it could be the angle of your cervix on that particular day (because it changes!) or the angle of your cervix on most days. All of these factors could impact the way your period product stays in place and does its job.

What’s most important to remember here is that there is absolutely NOTHING wrong with your body. If you’ve wrestled with it for hours, attempted and reattempted insertion many times over, talked to customer support, or run countless Google searches for tips and advice and it’s still a no-go… it could mean that the period product you chose isn’t the right fit for you as an individual.

Hitting a wall with a new product is never a fun experience. No one wants to feel like they’ve wasted money on an item they’ll never be able to use.

The thing is, most period product brands aren’t conducting extensive research prior to launching new products. What’s more, some of the most widely-used products have been manufactured using the same basic design as their earliest predecessor (case in point: tampons, which were patented in the 1930s… by a man). Throughout the 20th century, innovation in the period care space was largely stagnant.

This reality is part of what motivated us to launch the Flex® brand in 2016 with our original product, Flex Disc. With the disc, and with every product since, we’ve been determined to set a new status quo: Healthier periods for people and planet. And that means creating period products that work for every body.

How Flex Disc was created

Before we take any product to market, Flex conducts extensive research and testing to ensure that it suits the widest range of customers possible. There is no such thing as “one size fits all” in clothing or in period products—but until we’re able to manufacture period products in as many sizes as there are for, say, jeans sold at the Gap, we strive to get as close to “one size fits most” as we possibly can. It takes a little extra time and innovation, but the end result is worth it.

When we designed Flex Disc, we paid close attention to the materials that would make up the disc’s flexible rim. We chose a premium medical-grade polymer that was engineered to become more pliable as it warms up to body temperature. This helps the disc create a custom fit once inserted to seal off leaks and provide ultimate comfort. When you move around—at the gym, walking your dog, swimming, whatever—the disc moves and flexes with your body.

The disc’s pliability is part of what makes it so adaptable to multiple vaginal and pelvic ‘types’ and cervix positions. Fun fact: Did you know that there are four distinct pelvic shapes in people AFAB?

As of now, Flex Disc is only available in one size (with a 70mm rim diameter). It’s important to note that this size may be too large for younger teens who are menstruating but who may not be finished growing. We can confidently say, however, that Flex Disc was designed to fit 95% of vaginas.

Does Flex Disc work with a tilted (retroverted) uterus?

The angle of your uterus may or may not affect your disc’s ability to create a good seal. One in five people with vaginas has what’s known as a tilted, or retroverted, uterus. Instead of pointing forward toward the belly button, a retroverted uterus points in the opposite direction, towards the lower back.

While many of our customers with retroverted uteruses are able to use Flex Disc with no problem, you may have to experiment with different insertion methods to find the one that works best for you. When in doubt, you can always chat about this with your gynecologist. If the disc seems like it just won’t stay in place no matter what you try, you may find that Flex Cup is better suited for your anatomy.

Can I use Flex Disc with a high or low cervix?

Flex Disc works great for most cervix heights—however, there are other factors that might impact the fit of the disc when your cervix is higher or lower than ‘average.’ Where your pubic bone sits, the angle of the cervix and/or uterus, and the space in your vaginal fornix will all have an influence.

To get an approximate measurement of the depth of your cervix, take a look at the diagram below:

Even with a high cervix, you can still use Flex Disc with success. The most important thing to remember is that you want the disc to fully cover the cervix, wherever that may be for your anatomy. For removal, just remember to relax and bear down with your pelvic floor muscles to help move the disc closer to the vaginal opening so you can reach it easily.

With a low cervix, the trick is making sure the disc is pushed all the way back into the posterior fornix and that the front rim is tucked securely up behind your pubic bone. Want more tips and tricks? Email us at, or get in touch via the chat button on our homepage.

Flex Cup’s inclusive design

At first glance, Flex Cup looks about the same as any other bell-shaped menstrual cup on the market. But take a closer look and you’ll notice something different: Flex Cup features a patented pull-tab (a.k.a. Release Ring™) that breaks the seal for you during removal.

The pull-tab threads through the base of the cup and connects to the inner rim. When it’s time for removal, users can simply pull down on the pull-tab by gripping it or by looping a finger through the ring. Doing so collapses the rim down and inwards towards the center, breaking the seal and keeping the cup’s contents neatly contained for a removal process that’s easier and less messy.

Before Flex Cup became part of the Flex family, it was known as Keela Cup. Keela founder Jane Hartman Adamé got the idea for a new cup because she has Ehlers-Danlos Syndrome, a connective tissue disorder that made it hard for her to remove other menstrual cups. Keela was acquired by Flex in 2018; both Adamé and her co-founder, Andy Miller, have remained an integral part of the Flex team as full-time employees ever since.

The traditional menstrual cup must be removed by using two fingers to grip the base, manually break the seal, and carefully guide the cup out while avoiding spills. This process can be challenging for individuals with conditions that impact dexterity or fine motor skills (and, TBH, it can be a pain even for those without a disability).

Flex Cup’s unique design is unlike any product on the market because it makes removal easier and usage more accessible for people with and without disabilities. It’s another example of how Flex is working to transform the period industry for the better—creating period products for all.

What about sizing?

Flex Cup is available in two sizes. Size 1 (formerly Slim Fit) has a capacity of 22mL and is 43mm in diameter and 46mm from base to rim. This size is ideal for beginners, younger menstruators, and those who have not given birth or who have a shorter cervix. Size 2 (formerly Full Fit) has a capacity of 30mL, is 46mm in diameter, and is 53mm from base to rim. We typically recommend Size 2 for individuals who have given birth vaginally more than once or who have an especially heavy flow.

Since we recognize that it might be tricky to guess the best size for your body if you’ve never used a menstrual cup before, every Flex Cup comes with our Perfect Fit Guarantee.

If your Flex Cup doesn’t feel right, reach out to our customer support team via email at, or get in touch via the chat button on our homepage). We’ll help you find a custom fit, whether that means trying a different fold, insertion position, or sending you a different cup size free of charge. There’s a learning curve to any new period product—but we’re here to empower you in becoming an expert cup user!

Period innovation is our #1 priority

We’re on a mission to help people with periods thrive, which means menstrual products are just the beginning. We believe in a world where vagina isn’t a bad word, where trans men and non-binary bleeders are part of the conversation, and where nobody is turned away from essential period care due to their financial situation.

Made in the USA & Canada
Because our production facilities are so close to our warehouses, we reduce energy usage and emissions that come from traditional transit.

More Flex = less waste
Flex Cup is a ZERO-WASTE product, and Flex Disc reduces waste by 60% compared to traditional period products. Supporting Flex means you’re supporting Mother Earth.

Sourced responsibly
Our materials are not just of the utmost quality, they are also ethically sourced and repurposed when possible. Our factory partners are at the core of our business, and we ensure they are treated with care and respect.

Learn more about The Flex Co. story here.

This article is informational only and is not offered as medical advice, nor does it substitute for a consultation with your physician. If you have any gynecological/medical concerns or conditions, please consult your physician. 

© 2021 The Flex Company. All Rights Reserved.