Flex claims to reduce period cramps and allow for no-mess period sex—here’s what I thought after trying it for a week.

Ever since I first got my period when I was 14, I’ve experienced cramps. Depending on my method of birth control (or lack thereof) over the years, the cramps have come and gone in different levels of severity. Recently, my cramps have been on the more painful end of the spectrum: A dose of ibuprofen helps me manage the pain but doesn’t completely eliminate the lower back aches and abdomen tightness I typically experience.

So, after hearing about Flex, a single-use menstrual disc ($15 for 8 discs; flexfits.com) that claims to lessen or get rid of period-related cramps, I was game to try it. I’ve been a tampon user since I started my period and figured inserting a disc up there wouldn’t be much different from my usual menstrual routine.

Other benefits: The company says you can have mess-free period sex using Flex, since it sits in the vaginal canal and the disc catches period blood while it’s still inside of you. What’s more, the disc can stay inserted for up to 12 hours as opposed to the normal eight hours for a tampon.

The insertion process

On the first day of my period, I woke up with cramps that were so horrible, I had to immediately get out of bed to take ibuprofen. I decided it was time to try Flex.

Flex is a small disc made of medical-grade polymer that's flexible enough to bend in half. Once I bent it to insert, I noticed it was about the size and shape of a regular tampon. As someone who has only ever used tampons before, this appealed to me over a menstrual cup.

The package I received in the mail came with eight discs and easy-to-follow instructions with both written directions and diagrams. Basically, you use your finger to push the disc into your vaginal canal and then angle it upwards so it sits in place against your vaginal fornix (where your cervix and vaginal canal meet). This means the disc will catch any blood or fluids before they get into your vaginal canal.

Insertion was similar to that of a tampon: it’s best to sit on the toilet, relax, then push it into place. On my first attempt, it felt lopsided, so I used my finger to better position it. Once the disc was in place, though, I couldn’t even feel it. At first, not noticing the disc freaked me out: what if it got stuck up there? Flex’s founders say you don’t have to worry about it getting stuck, but just to be safe I used my finger to check it was where I left it—and it was.

Credit: flexfits.com

Working out with the Flex

I headed to my weekly soccer league that evening with the same Flex disc I inserted in the morning. Usually, I change my tampons multiple times a day because they get oversaturated with blood. The disc, however, caught the blood high up so it felt more mess-free and stayed in place while I ran around. I could see why swimmers would benefit from using Flex over a tampon. It did slide out from my vangial fornix a few times throughout the 12-hour day, though, so I used my finger to push it back into place quickly.

Sex with the Flex

The creators of Flex say you can have sex with it in, so I decided to put it to the test. Spoiler: it is possible, but it’s not going to be the best sex of your life. Because your vaginal muscles contract around the disc to hold it in place, it feels pretty, well, tense down there the whole time. My partner said he didn’t feel the Flex at all during sex and it was indeed mess-free like the company claims. If you do enjoy or want to have period sex, the Flex could be worth a shot. If you could take or leave period sex, I would pass.

Removing the Flex

Removal was easier than expected. When I grabbed the disc with my finger, it kind of slid out on its own. I was expecting a major mess, so I sat on the toilet for removal, but in reality, the disc was covered in a thin layer of blood, not a pool of it. You can’t flush the disc like you can with tampons, so I wrapped it in toilet paper and put it in the trash.

Does it really help with cramps?

The creators of Flex claim that the disc can reduce menstrual cramps for some, since unlike a tampon, which is stiff, the disc is flexible and "moves with the contractions of your body, helping to ease or eliminate the pain of cramping." But when I reached out to Donnica Moore, MD, a gynecologist and host of the podcast In the Ladies' Room with Dr. Donnica, she was skeptical about these claims, noting that tampons don't cause menstrual cramps. "[Menstrual cramps] happen in the uterus in order to expel its lining, not the vagina, where the Flex disc or tampons are placed," Dr. Moore explains.

What's more, she says, your body produces higher levels of prostaglandins, a hormone-like substance that causes pain and inflammation, when you're on your period. This means menstrual products like tampons or Flex discs can't create or affect the cramps you feel. If you want to reduce cramps, your best bet is an NSAID (non-steroidal anti-inflammatory medicine) like ibuprofen or an oral contraceptive, says Dr. Moore.

Throughout my week of using Flex, though, I did notice that my cramps were less severe. It didn’t cure my cramps entirely, but I didn’t feel the intense pain I usually do. My period also ended a couple of days earlier than when I used tampons, which I found interesting. Overall, I think the Flex is great for someone who wants to have period sex or get away from constantly have to change tampons.

However, if you’re searching for an eco-friendly period product, Flex isn’t the one. Unlike regular menstrual cups, you can only use each disc once and then have to throw it out. You also have to order a new package online each time you run out of discs, which might not be the most convenient option for some people.