Menstrual cup leaking? You're not alone: leaks are one of the most common reasons people give up on cups, and it's almost always fixable. Leaks usually come down to one of a few things: the cup hasn't opened fully, it's sitting in the wrong place, it's full, or it's the wrong size for you. Here's how to find the cause and fix it.
First, a quick check. When you remove your cup, look at how full it is.
- Nearly full or overflowing? Go to causes 1 and 2.
- Leaking but half empty or less? Go to causes 3 to 7.
- Leaking only at certain times, such as at night, during sport or after the toilet? Go to causes 6 and 8.
1. Your cup is full: empty it more often
Lunette cups can be worn for up to 12 hours, but that's a maximum, not a schedule. On heavy days you may need to empty your cup much more often. If it's three-quarters full or more when you take it out, empty it sooner next time.
Local rules in some countries (including France, Germany and Australia) set the limit at 8 hours, and in France overnight use isn't recommended.
The measuring lines on the cup help you learn your own flow: Size 1 has lines at 5 ml and 13.5 ml, Size 2 at 7.5 ml and 15 ml.
2. You might need a different size
Lunette comes in two sizes, and the right one depends on your flow and your body:
- Size 1 (25 ml, 41 mm rim, softer): for a light to medium flow, a low cervix, teens, strong pelvic floor muscles or a sensitive bladder.
- Size 2 (30 ml, 46 mm rim, firmer): for a heavier flow or a higher cervix.
If your Size 1 cup regularly fills before you can empty it, or leaks even when it's open and placed correctly, Size 2's extra capacity and wider, firmer rim may help. Our menstrual cup size guide walks you through the choice.
3. Your menstrual cup isn't fully open
A cup that hasn't opened all the way can't seal against your vaginal walls, so blood slips past it. This is the most common cause of leaks in the first few cycles.
After inserting your cup:
- run a clean finger around the base and rim. It should feel round and smooth. A dent or fold means it hasn't opened.
- rotate the cup gently by its base, a full turn if you can.
- pull it down very slightly and let go, or tense and relax your pelvic floor muscles. Both help it pop open.
- try a different fold. The punch-down fold and the 7-fold open more easily for some people than the C-fold. See how to use a menstrual cup for the folds.
4. Your cup is sitting next to your cervix
Your cup should sit below your cervix, so the cervix is above the rim or slightly inside it. If the cup sits off to one side, blood from the cervix can flow down outside the cup.
- Find your cervix during your period: it feels like a firm, round bump, a bit like the tip of your nose. Our guide on how to find your cervix explains how.
- Insert the cup lower than you would a tampon, angled towards your lower back rather than straight up.
- If you have a low cervix and the stem bothers you, you can trim it.
5. You're inserting it at an awkward angle
Your vaginal canal angles back towards your tailbone, not straight up. Aim the folded cup towards your lower back. Squatting, or sitting on the toilet with your knees apart, tilts your pelvis and often makes insertion easier and the seal better.
6. Your cup moves during the day
Pelvic floor muscles, a bowel movement or heavy exercise can push the cup lower or tip it slightly, which can break the seal.
- After a bowel movement, wash your hands and check the cup is still in place. Push it gently back up and rotate it if needed.
- If your cup keeps slipping down even when it's fully open, try placing it a little higher, and check your size: Lunette recommends Size 1 for strong pelvic floor muscles, and the size guide walks you through the choice.
7. The air holes are blocked
The small holes under the rim help the cup open and form a seal. If they're blocked, the cup may not open properly.
To clear them, fill the cup with water, cover the top with your palm, turn it over and squeeze, so water is forced through the holes. Don't use pins, needles or toothpicks, because they can tear the silicone. Read how to clean your menstrual cup for the full routine.
8. It leaks at night or during sport
Lying down changes the angle of your vagina, and long hours plus a heavy flow mean the cup can overflow. Empty it right before you go to bed and again first thing in the morning.
For sport, the cup can be worn for running, yoga, swimming and more. Check it's fully open before you start.
On your heaviest nights, or while you're still learning, a back-up helps. Lunette Period Panties handle light to medium flow on their own and are designed to be worn with your cup.
9. You're still learning (and that's normal)
Many people need two or three periods to get used to a cup. Practise on a lighter day at home, when you're relaxed and not in a hurry, and try different folds and positions until one feels right.
Some people find that pelvic floor exercises help the cup feel more secure. If you've recently given birth, follow the advice of your midwife or doctor before using any internal period product.
Still leaking? The fit promise
If you've worked through these causes and your cup still leaks, the size may not suit your body. If your Lunette cup clearly doesn't work for you after a fair try of two to three cycles, Lunette will refund it or send you the other size. Compare both sizes on the Lunette menstrual cup page.
Menstrual cup leaking: frequently asked questions
Why is my menstrual cup leaking even though it's not full?
Most often the cup hasn't fully opened, or it's sitting next to your cervix instead of below it, so blood runs past the rim. Run a finger around the rim to check it's round, rotate the cup gently, and try placing it a little lower.
How do I know if my menstrual cup has opened?
Run a clean finger around the base and the rim. It should feel round and smooth, with no folds or dents. You can also rotate the cup gently by its base, or pull it down very slightly and let go, which helps it pop open.
Should I use a bigger menstrual cup if it leaks?
Only once you've ruled out the other causes. If your Size 1 cup fills before you can empty it, or leaks even when it's open and placed correctly, Size 2 holds 30 ml instead of 25 ml and has a wider, firmer rim. If you're unsure, Lunette's fit promise lets you swap sizes after a fair try of two to three cycles.
Why does my menstrual cup leak at night?
Lying down changes the angle, and a cup that's nearly full can overflow. Empty it right before bed, and on heavy nights wear period underwear as a back-up.
Do menstrual cups leak?
They can, especially while you're learning, but a cup that's the right size and fully open usually doesn't. Most leaks happen because the cup hasn't opened, sits next to the cervix instead of below it, is full, or is the wrong size. The causes and fixes are the same for any brand of cup.
photo: courtesy of Pinterest
