Jean Hailes for Women's Health puts it plainly in its first-timer guide: once the cup is in the right spot, you shouldn't feel it, and you shouldn't have any leaks. So if your menstrual cup is leaking, something about position, timing or size is worth a second look. The fix is rarely complicated.
Quick answer: A period cup leaks when it overflows, when it hasn't fully unfolded, or when it sits beside the cervix instead of beneath it. Empty it more often, feel around the base to confirm it has popped open, and look at Lunette Size 2 if your flow is heavy or your cervix sits high.
Why does my period cup leak?
Most leaks come down to one of four things, and you can check each in a minute or two.
- It's overflowing. In Australia the Lunette period cup can be worn for up to 8 hours. Jean Hailes says you may need to empty a cup 2 to 4 times a day, depending on your flow.
- It hasn't unfolded. Feel around the base with a finger. If the cup is still folded, Jean Hailes suggests gently twisting the base, or removing it and trying again.
- The angle is off. Insert it rim first, angled towards your tailbone, so the stem sits just inside your vagina.
- The air holes are blocked. Lunette's care page asks you to check that the little holes under the rim are open. Fill the cup with water, cover it with your palm, flip it and squeeze so water squirts through. Never use a needle or anything sharp.
Why is my menstrual cup leaking when it's not full?
If there's room left in the cup and you still leak, it most likely hasn't opened fully or is sitting off-centre next to your cervix. Take it out, refold it, reinsert it and check the base again.
Does cervix height affect leaking?
Yes, because the height of your cervix shapes which size suits you. Lunette recommends Size 1 for a low cervix and Size 2 for a higher one. Our article on high cervix, low cervix and your menstrual cup walks you through finding yours.
Which Lunette size stops leaks?
The size that matches your flow and body. Jean Hailes notes that cups come in different shapes and sizes to suit your body and your periods, and Lunette makes two:
| Size 1 | Size 2 | |
|---|---|---|
| Suggested for | Light to medium flow, a low cervix, teens, strong pelvic floor muscles, a sensitive bladder | Heavier flow or a higher cervix |
| Holds | 25 ml | 30 ml |
| Width | 41 mm | 46 mm |
| Feel | Softer silicone | Firmer silicone |
Each size holds more than 2 to 3 tampons' worth. If the cup clearly isn't working after a fair try of two to three cycles, Lunette can refund it or send the other size.
When to see a doctor
Leaking can also mean your periods are heavier than a cup alone can handle. Healthdirect lists these signs of heavy periods:
- Needing to change a tampon or pad every 1 to 2 hours.
- Needing to change a tampon or pad overnight.
- Passing clots larger than a 50 cent coin.
- Bleeding through your clothing.
See your doctor if you have these symptoms or your periods affect your everyday life, and get urgent care for bleeding that is suddenly much heavier than usual. For extra cover in the meantime, healthdirect suggests pairing a tampon or menstrual cup with a pad or period underwear. If you have a sudden high temperature, vomiting, dizziness or a sunburn-like rash while using a cup, call triple zero (000), as healthdirect advises for toxic shock syndrome.
Frequently asked questions
Do period cups leak?
A period cup that fits well and is emptied in time shouldn't leak. Leaks are common in the early weeks while you learn how to fold and place it. Check that it has opened, that it is angled towards your tailbone and that you're emptying it before it fills, especially on heavy days.
How long can I leave my Lunette period cup in?
In Australia, Lunette says its period cup can be worn for up to 8 hours. On heavy days you may need to empty it sooner. Jean Hailes advises never leaving a menstrual cup in longer than recommended and following the product instructions for removal and cleaning each time.
Why do I leak when I sneeze, run or stand up?
Movement can expose a cup that's sitting low, hasn't unfolded or is resting beside the cervix. Take it out, reinsert it at an angle towards your tailbone and feel the base to confirm it's open. If leaks keep coming back with movement, the other Lunette size may suit your body better.
Ready to find your fit? Use our period cup size guide, then choose Size 1 or Size 2 on the Lunette period cup page.
This article is general information and isn't medical advice. Please see your GP if your periods, bleeding or pain concern you.
