FAQs

Menstrual cups are small, medical-grade silicone devices that are inserted into the vagina to collect menstrual fluid. One cup can be reused for 10 years, and can safely stay in for up to 12 hours at a time.

Menstrual cup capacities vary depending on brand and size: Size 0 / Teen: 18ml or 2-4 tampons Size 1 / Small: 25ml or 3-5 tampons Size 2 / Large / Regular: 30ml or 4-6 tampons

Everyone’s flow is different. Some people may need to empty their cup every few hours, while others can go much longer. You must empty and clean it at least every 12 hours. We recommend checking it periodically on your first couple of uses to see how full it gets and figure out what works best for you.

Yes! Menstrual cups are safe to wear overnight and can stay in for up to 12 hours. If you have a heavy flow, you might want to wear period underwear as a backup—just in case. Most people find cups reliable and mess-free while sleeping.

Nope! You can pee or poop without removing your cup. It sits in the vaginal canal, which is separate from where urine and stool leave the body. If it feels like it shifted a bit, you can adjust it or check the seal after. Some people find it helpful to do a quick check after using the bathroom, just to make sure it’s still in place.

Yes! You can insert your cup ahead of time to avoid any surprise leaks. If you’re feeling dry, try using clean water or a little water-based lube (without glycerin, parabens, or propylene glycol) to make insertion easier and more comfortable.

Before using your cup for the first time, it’s important to sanitize it. You can either: Boil it for 4–5 minutes Tip: place it in a whisk or tongs to keep it from touching the bottom of the pot. Wipe it with 70% isopropyl alcohol and let it dry completely so the alcohol can fully evaporate. You can choose to sanitize using these methods in between cycles if you'd like although cleaning with soap and hot water suffices.

Wash your hands, then fold the cup (most people use the “C-fold” or “punch-down” fold) and gently insert it into your vagina, aiming toward your tailbone. Once inside, the cup will open and form a seal against your vaginal walls to collect blood. You shouldn’t feel it once it’s in place. To remove, wash your hands, pinch the base of the cup to release the seal, and gently pull it out. Empty the contents into the toilet, rinse, and reinsert.

A menstrual cup cannot get stuck inside you. Your vaginal muscles naturally expand and contract, and your cervix moves up and down. If you’re having trouble reaching the cup for removal, try bearing down with your pelvic muscles to help bring it closer.

If your cup is leaking or slipping out, make sure it’s inserted correctly and has fully opened to create a seal. You can also check for any damage or wear on the cup. If problems continue, it might be the wrong size for you—reach out to The Flow or the cup manufacturer for additional support. Don’t worry if it takes some time to get used to; using a cup can have a bit of a learning curve, so give yourself time to adjust!

It can be a little messy at first, especially while you're learning how to insert, remove, and clean it. Like anything new, it takes a bit of practice! To make things easier, try using a water-based lubricant when practicing insertion (even when you’re not on your period), and consider removing the cup in the shower until you get the hang of it. Most users find that with time, it becomes quick, clean, and easy.

A menstrual cup shouldn’t hurt. If you have the right size and it’s inserted properly, you shouldn’t feel it at all. If you’re feeling any discomfort, it might be a sizing or placement issue, and a quick adjustment usually helps. With a little practice, most people find cups very comfortable to use.

Yes! You can use a menstrual cup even if you’ve never had sex. It might stretch the hymen—a thin piece of tissue near the vaginal opening—but that doesn’t mean you’re no longer a virgin. Hymens can stretch from everyday activities like sports or using tampons, too. Virginity is about whether someone has had sexual intercourse, not about using period products. Choosing a menstrual cup is just about finding what works best for your body.

An IUD sits inside the uterus, while a menstrual cup sits in the vagina—so they’re in two separate places and generally don’t interfere with each other. However, to be safe, it’s important to break the cup’s seal before removing it to avoid any tugging on the IUD strings. If you’re concerned, talk to your healthcare provider before using a cup with an IUD.

After emptying your cup, simply rinse it with cold water first (to help prevent stains) and then wash it with warm water and a mild, fragrance-free soap. Be sure to rinse thoroughly so no soap residue is left behind. If you don’t have access to water, you can wipe the cup with toilet paper or a clean tissue and wash it when you’re able.

You should empty and rinse your cup every 8–12 hours, depending on your flow. Some people with heavier periods may need to empty it more frequently. Between cycles, it’s important to clean your cup more thoroughly.

To keep your cup free from odor, don’t wear it for more than 12 hours at a time. When you remove it, rinse with cold water first, then wash with a mild, oil- and fragrance-free cleanser. If your cup develops an odor, try placing it on a sunny windowsill for a day or two. Still noticing a smell? You can soak it in 3% hydrogen peroxide for up to 8 hours. Just keep in mind that soaking your cup too often can cause wear over time, so we recommend doing this only when needed—no more than every 3–4 months. After soaking, leave it in the sun again to fully air out.

Menstrual cups can last up to 10 years, but it’s time to replace yours if you notice any of the following: strong or lingering odor, heavy staining that won’t come out, white powder, flaking, or a grainy texture, cracks, tears, or damage to the rim or stem, or sudden leaking that didn’t happen before.

Yes! Period odor happens when menstrual blood mixes with air and natural bacteria. This is common with pads, since the blood is exposed outside the body. Menstrual cups sit inside the vaginal canal, so the blood isn’t exposed to air—leading to much less odor. That said, no matter what period product you use, try to avoid scented products—they often contain harmful chemicals. And remember: any odor during your period is completely normal. It’s just part of a healthy, natural biological process.

Yes, it’s totally normal for a menstrual cup to change color over time. Staining happens from the iron in your flow and regular use, especially with lighter-colored cups. It’s purely cosmetic and doesn’t affect how the cup works. To help prevent staining, rinse your cup with cold water first, then wash with hot water and a fragrance- and oil-free soap.

Cups can last up to 10 years, but when it’s time to replace yours, there are a couple of options: Burn it: You can safely burn a silicone cup down to ash. Since medical-grade silicone comes from silica (like sand), the ash isn’t harmful to the environment. Cut and toss: You can also cut the cup into smaller pieces and throw it away. While silicone isn’t easily recyclable, it does break down over time—unlike tampon applicators and wrappers, which can pollute the environment. Recycle (if available): Some cup brands offer recycling programs – look on their website to see what they might have available!

Yes! Menstrual cups are considered Class II medical devices by the FDA, meaning they meet safety and effectiveness standards. When a brand says their cup is “FDA approved,” it means the cup has been cleared by the FDA to be sold in the U.S. Always look for this when choosing a cup!

You shouldn’t use a standard menstrual cup during penetrative vaginal sex. Cups sit in the vaginal canal and take up space, which can make sex uncomfortable or even painful. While the cup won’t get lost inside you, it’s best to remove it before any kind of penetration. (Some people use soft menstrual discs designed for mess-free period sex—but that's a different product!)