A cup that breaks the suction and removes like a tampon? That’s the FLEX Cup.
The FLEX Cup’s Unique Features

The FLEX Cup, not to be confused with the FLEX Disc, is a reusable menstrual cup that comes in two sizes, Slim Fit and Full Fit, Slim fit is the smaller size and has a smaller capacity 22 ml, than the Full at 30 ml.
Related Resource: Menstrual Cup Chart
The most notable part of this cup is it’s looped stem that, when you pull on it during wear, is designed to pull down one section of the rim to break any suction the cup has in your vagina. This can be a huge advantage for anyone with muscle weakness in their hands, joint pain, and other disabilities that could make removing a traditional cup uncomfortable or difficult. It’s also a cup to try if you’ve consistently had a cup seal so strongly that you find removal to be a chore. A cup that breaks the suction and removes like a tampon? That’s the FLEX Cup.
This stem doubles as being somewhat customizable in length if you need to shorten it, but be warned if you do this you lose space inside the cup and potentially face an issue where this bumps into the cervix if it’s lower and dips inside the cup. In other cup designs it would have space, but potentially not in this one.
The stem is about 28 mm long at its shortest length and about 47 mm at the longest length. This length includes the nub on the base that protrudes from the body of the cup. Other cups with long trimmable stems include the XO Flo, and the KIND Cup. In the image below, you can compare FLEX Full Fit to other cups in the “high cervix” range, which either have longer stems and/or long bodies. All of these cups would be good options for a high cervix when reaching cups is an issue.

At its shortest stem length, the FLEX Cup is still not short enough to work for those who have a lower cervix or even “average low” like me, especially when you add in the internal loop that can prevent the cervix from dipping inside the cup.
The stem pulls through a hole at the base of the cup. It’s perfectly fitted so leaks won’t happen but cleaning needs to be done thoroughly and carefully.

The cup is black and solid to fit the Flex aesthetic, so seeing buildup around these pieces not common on other cups is harder. You practically have to use a flashlight to ensure the cup is clean, it’s a black hole and no light goes through the cup since it’s fully tinted with no transparency. If you like to measure your period then this cup is not for you.

In firmness, I would say this cup falls in the “average” range… it’s not even a firm or soft average, it’s average just like a Diva Cup. That puts it softer than a Saalt Regular and firmer than a Saalt Soft. The body of FLEX Cup is a bit softer than the body of The DivaCup but their rims are virtually identical in their firmness, so I feel confident in saying FLEX Cup is dead center “average” firmness which is perfect for first-time cup users.
A “Short” History of The Flex Company

FLEX started as a company selling their version of the disposable disc, they called it the FLEX Disc and it was modeled almost exactly after the pink rimmed Softcup (now named Softdisc). Virtually identical minus the color of the rims and the claim that FLEX’s rim “molds to your body.” The company launched out of the gate promoting this product as only for mess-free period sex, with barely any mentions of it working for regular period protection. Later on the messaging changed, but that is how it started and the marketing was quite off-putting. Discs are a great option for period sex, but the implication that it’s a secret shame that you can hide from your partner, or that it’s to protect them from getting messy, didn’t land well with me. They also marketed to say their discs were better than menstrual cups and had multiple times claimed cups were not a good period option compared to their discs. It’s possible this tactic was less about it being JUST for period sex and more to be a differentiating factor against the Softcup, since the products were otherwise identical. Softcup was marketed for periods, FLEX was marketed for “period sex” at first. Flex was a subscription model only at the time, Softcup was on retail shelves.


In early versions of their website they continually refer to their disc as “soft and flexible” and menstrual cups as “hard” and “worsen cramps.” They consistently compared the two products this way to make their discs more appealing. As cup users know, the claim that menstrual cups “maintain their hardness inside of your body” is not at all true in most menstrual cup options, save for the firmest models. And in my personal experience, the FLEX Disc wouldn’t qualify as “soft” or “flexible,” especially compared to the flexibility and softness of silicone menstrual cups.
So of course it was shocking when they announced their new menstrual cup, FLEX Cup. The brand didn’t acknowledge until after their initial email that the cup they were launching was actually the Keela Cup, first introducing it as their own new innovative design. On their current website, menstrual cups are given a kinder treatment compared to the way they described them prior to releasing their own.
The Keela Cup design was a successfully funded Kickstarter cup that was apparently struggling to bring the cup to market even with their campaign funds. I don’t know the behind-the-scenes affairs but FLEX Company offered to acquire the design and sell under their brand and assist in fulfilling the Kickstarter Keela Cups in their original color for backers first. On a side note, FLEX ultimately ended up acquiring Softcup in 2016, the product they essentially copied to create their own disc. In a letter issued by the new owners of Softcup (later renamed Softdisc) it was noted by Lauren, founder of Flex, “I’m a huge fan of Softcup, and in many ways, its features and functionality served as an inspiration for me when I decided to create my own menstrual product…” FLEX still owns and operates Softdisc.
The Keela, and by extension the FLEX Cup, has good design intent behind it but that design and intent weren’t from FLEX, it was from Jane and her team. There are interviews with Keela Cup’s designer Jane online available to read for more context if you’d like.
Jane, the Keela Cup designer, has Ehlers-Danlos syndrome, a connective tissue disorder characterized by joint instability. She and others like her with mobility and gripping issues or muscle weakness and other accessibility challenges found traditional cups hard to remove. That is where the suction pull method came into play. It’s a smart design but not without its flaws.
My Flex Cup Review
The cup functioned and felt like any other cup. For folds I used the punchdown, depending on how short you make the stem you may have to play around with folds to see what works for you when there is an extra tube inside the body of the cup.
I am always a stem chopper and remove the entire stem on all cups. For obvious reasons, you can not do that with this cup. If you push the stem as high into the cup as it will go you still have some length on the stem (about 28 mm, un-trimmable), and you have the loop inside.
I have a “low average” cervix towards the beginning of my cycle so I had a challenge on the first day to fit it comfortably and not be bothered by it feeling low. In fact, I recall at least twice having to deal with the stem poking out slightly. It’s flexible enough I was able to live through it but I was not happy about it, yet powered through to be able to actually review the cup. Outside of my lowest days when I used it, I have to say it wore like any other cup, in terms of comfort. I didn’t have leaks with this cup (I think I even forget to say that in the video!) and it functioned as well as some of my best cups. It’s just far too long of a cup.

Removing the FLEX Cup
This is the thing that you likely bought the cup for. YES IT WORKS. Pulling the stem will very likely break the suction for you as designed.
Still, you will want to only pull the stem until the suction breaks. You can continue pulling to get the cup low enough to reach it if you need to. Once the base is near your vaginal entrance you will want to grab the base and pull down the rest of the way with a solid grip, keep it level, then dump. Don’t simply pull the entire cup down and out by the stem, that would be a blood bath. I demonstrate this in the video.
The benefits of the cup’s design also lead to flaws that a user may experience. Cleaning is a bother (I imagine many will get a bit lazy and stop removing and re-threading…) and after removing you will have to pull the stem back to your original length and remember what length it is you want it to be. A traditional cup, while not offering the suction release and adjustable stem, is simply easier and more convenient to deal with if you don’t need the features the FLEX Cup offers.
I will admit that in my years of cup use there have only been a few cups to suction and seal to the point of having a hard time releasing that suction. A pretty simple pinch has always been enough. After experiencing a hard to undo suction I fully appreciate the fact that some people have that all the time and it is quite awful and stressful to deal with.
Who is FLEX Cup Good For?
So who would I say this cup is good for? It’s good for people who have had trouble breaking their cup’s suction and it continues to be an issue. It’s good if you find pinch and grasping your cup hard to accomplish due to muscle weakness or pain. It is good if you have a higher cervix or average height cervix. The capacity puts it in line with other brands.
Final Thoughts and a Positive Note
I recognize and appreciate the design of the FLEX Cup (or rather, the Keela Cup’s design innovations) so for that reason, this feels like an overall positive review. It’s a feat of manufacturing and engineering and one that was made possible by Flex when they purchased the Keela design. I want people to experience a better period with safe products that work for them. If that ends up being the FLEX Cup that is ok with me… I included the FLEX Cup in the possible outcomes on The Period Nirvana Quiz because it does serve an important function that may help people succeed with cups. That, of course, is my goal.
One positive thing about the FLEX Company buying Instead/Softcup – they made a concerted effort to distinguish menstrual discs from menstrual cups. Their decision to rename Softcup as Softdisc, and call both brands “menstrual discs” (now that they owned both) made a lot of sense. As an educator, I often run into people saying they had a poor menstrual cup experience only to dig in and find out they had tried a Softcup, a product that functions very differently than a cup.
Images from FlexFits.com and Softcup.com used in this post and video were pulled from the Internet Archive. The Internet Archive saves websites and enables you to view webpages as they were on any given date from the past which enabled me to bring you glimpses of the FLEX Company’s position against menstrual cups prior to 2017.
I have been intrigued by period cups for a few years and finally found the courage to begin using one myself this January, when I realized that spending more time with intimate features of my body could help relieve certain fears that I have related to healthcare/hospital experiences (blood draws, IV’s etc.) and I don’t want to be held captive by my fears. I will be going to college in a couple of weeks, and I also wanted a way to wear something other than a hit-or-miss pad to bed. I thank Kim Rosas for this site and her years of videos for my successes on my exploration with my fears, and have read this review to try the Flex cup in the hope that it will be finally for me, over the Soft Cup Small, because I have a hard time getting my cup out. Otherwise, this has been a very healthy and fun 2021 when thinking about my new period related skills. I bought the Flex Cup a week ago after watching Period Nirvana videos on Instagram and thinking that the Flex Cup sounded right for me, and I just took the quiz for the first time, and, (congratulations Kim Rosas!) The quiz told me the same thing. Now to keep waiting patiently for my period! Again, thank you so very much.
It sounds like you’ve been on quite a journey. I am honored to be part of your success, and love to hear these types of stories. Best of luck reaching period nirvana and best of luck with college! Please keep us updated on your journey with our facebook group.