Does a Menstrual Cup Leak?
How to Diagnose + Common Solutions
“Does a menstrual cup leak?” This is one of the most common questions we receive at Feminy. The good news: a properly used menstrual cup should not leak. If you’re experiencing leakage, chances are it’s just one small thing that needs adjustment.
But before solving the problem, you first need to diagnose what type of leakage you’re experiencing. Different causes show up in different ways — and require different solutions.
Before jumping into the causes, observe your leakage and ask yourself these questions:
| What you see | Possible cause |
|---|---|
| Cup is nearly empty, but there’s blood on underwear | No suction seal |
| Cup is full when removed | Capacity issue — need to empty more often |
| Leak happens right after insertion | Cup didn’t open fully or placement is off |
| Leak happens during exercise | Cup may be too soft or too small |
| Leak with pressure or discomfort | Cup may be too large or placed too high |
| Leak only on certain days | Cervical height changes — adjust placement |
| Leak after a bowel movement | Seal temporarily broken (needs repositioning) |
| Difficulty peeing or feeling of incomplete bladder emptying | Cup is too large — pressing on bladder |
1. After insertion, your cup may not have fully opened and created a proper suction seal.
How to check:
Run a finger around the base of the cup after insertion. If you feel any folds, dents, or flat spots, the cup hasn’t fully opened. It should feel round, full, and springy.
Solution:
Gently pinch the base of the cup (not the stem) and give it a little twist. This usually helps it pop right open. You might even hear a satisfying little “pop” — that’s the sound of a good seal being formed.
2. A cup that’s too small may shift around or leak around the sides. A cup that’s too large may not open fully, cause pressure, or press on your bladder.
How to check:
If you feel discomfort or pressure after insertion, or if your cup keeps sliding down, the size may be off. Also, if you have to strain to pee or feel like you can’t fully empty your bladder, your cup might be too large.
Solution:
Choose a size based on your cervical height and whether you’ve given birth vaginally. Most brands offer a “small” (under 30 / no vaginal birth) and a “large” (over 30 / have given birth). When in doubt, measure your cervical height first — it’s the most reliable way to find your fit.
3. The cup isn’t sitting correctly around your cervix — it may be too high, too low, or at the wrong angle.
How to check:
After insertion, feel the base of the cup and locate your cervix. You should feel that your cervix is fully inside the cup (like a lid covering it). If your cervix is sitting outside the cup or the cup is poking into it, the placement is off.
Solution:
When inserting, aim down and back (toward your tailbone), not straight up. The stem should sit just inside your vaginal opening — not sticking out, not completely hidden. If it doesn’t feel right, take it out and try again. A few practice rounds and you’ll get the hang of it.
4. There are a few small holes just below the rim of your cup — they help create a proper suction seal. If they get blocked, the seal won’t work.
How to check:
When you’re cleaning your cup, hold it up to the light and look at those little holes. If you see any blood, a white film, or gunk inside them — they’re clogged.
Solution:
Fill the cup with water, seal the rim with your palm, and squeeze firmly. The water will shoot out through the holes and clear the blockage. You can also use a small brush (like a bottle brush or a dedicated cup brush) to gently scrub around the holes. Keep those holes clear, and your seal will be good to go.
5. On heavy flow days, your cup may fill up before the 12-hour mark, causing overflow.
How to check:
When you remove your cup, look at how much blood is inside. If it’s nearly full (close to the rim) , overflow is the culprit.
Solution:
Empty every 4–6 hours on heavy days. Menstrual cups hold 3x more than tampons, but that doesn’t mean you can set it and forget it — they can still fill up. If you find yourself needing to empty constantly, consider switching to a larger capacity cup.
6. If you have a low cervix, a standard-length cup may stick out, not sit properly, or feel uncomfortable.
How to check:
During your period, insert a finger into your vagina and feel for your cervix. If you can reach it before your finger is halfway in (it feels like a small bump, similar to the tip of your nose), you have a low cervix.
Solution:
Use a short / low-cervix menstrual cup. These cups are typically shorter and wider, designed to sit comfortably in a lower position. Feminy offers sizes to fit different anatomies — including low cervixes.
7. Intense exercise, bearing down during a bowel movement, sex, or strong pelvic floor contractions can temporarily break the seal.
How to check:
If leakage happens right after a workout, a bowel movement, or sex — and the cup isn’t full when you remove it — the seal was likely temporarily broken.
Solution:
Check the cup’s position and gently rotate it to re-establish the seal. If leakage happens only when you use the bathroom (and only then), that’s normal “auto-dumping” — not a problem at all. If it’s happening during exercise, consider switching to a firmer cup that holds up better against muscle contractions.