Why is my menstrual cup leaking? Causes and What to try

11 min read
Menstrual Cup leaking

Menstrual cup leaking is common, especially while you are learning, but the timing and amount of the leak can help you work out what is happening. Your cup may not be fully open, your cervix may be sitting beside it or the cup may simply be overflowing. In some cases, a small amount of residual blood can look like a leak even when the cup is working correctly.

Before changing your technique or buying another cup, notice when the leaking starts and whether the cup is empty, partly full or overflowing when you remove it. Those details provide useful clues.

Why is my menstrual cup leaking?

What happens Possible explanation What to check first
A few spots appear shortly after insertion Residual blood may be sitting below the cup Check whether the spotting stops rather than becoming an ongoing leak
Leaking starts almost immediately and the cup is mostly empty The cup may not be fully open or the cervix may be outside it Check the cup body for folds and confirm the cup is positioned below or around the cervix
Leaking starts after several hours and the cup is full The cup has probably overflowed Empty it sooner and compare its usable capacity with your flow
The cup leaks well before it is full Its position, opening or fit may be affecting the seal Check the cervix position, cup shape, diameter and firmness
It leaks mainly during exercise or movement The cup may be compressing, shifting or losing its seal Consider whether a different firmness, shape or diameter would feel more stable
It leaks on some days but not others Your flow or cervix position may be changing during your period Notice whether the cup is full and check your cervix height on different days

Is your cup leaking or is it residual blood?

A small amount of spotting after insertion does not always mean your cup is leaking. Menstrual blood can remain in the vaginal canal below the cup and appear later on toilet paper, a liner or your underwear.

After inserting the cup, wipe away any blood around the vaginal opening. If it is comfortable to do so, you can also run a clean finger around the lower part of the cup to remove blood sitting below it.

Residual blood usually causes light spotting that settles. If the bleeding continues, becomes heavier or the cup contains very little blood when you remove it, check the cup’s opening and position.

While you are learning, you may prefer to use a cloth pad or liner as backup protection.

The cup has not fully opened

A menstrual cup needs to unfold sufficiently to collect menstrual flow and form a seal. However, it does not have to make an audible or noticeable “pop”. Softer cups in particular may open quietly.

How to check whether your cup is open

After insertion, use a clean finger to feel around the body or base of the cup. It should generally feel rounded rather than sharply folded. A small amount of flattening can be normal depending on the cup and your anatomy, but a deep indentation may indicate that part of the cup is still folded.

You can also hold the base and apply a very gentle downward tug. Some resistance suggests that a seal has formed. Do not pull firmly and always release the seal before removing the cup.

What to try if the cup remains folded

  • Try a different menstrual cup fold. One fold may open more readily for you than another.
  • Adjust the insertion angle slightly towards your tailbone.
  • Press gently against the vaginal wall beside an indentation to give the cup more room to expand.
  • Move the cup slightly lower or higher and allow it to settle naturally.
  • Hold the base and turn it slightly if it moves comfortably. A full 360-degree rotation is not required.
  • If a very soft cup repeatedly stays compressed, consider whether a firmer cup would open more readily.

Do not force the cup to open or repeatedly squeeze your pelvic floor muscles. If insertion or adjustment is painful, remove the cup and try again later.

The cervix is outside the cup

If your cup leaks almost immediately but contains little menstrual fluid when you remove it, your cervix may be sitting beside the cup rather than above or partly inside its opening. Menstrual flow can then travel down the outside of the cup.

The cervix does not always point straight down. It may angle forwards, backwards or to one side and its position can change during your menstrual cycle.

How to check the position

Before inserting the cup, wash your hands and gently locate your cervix with a finger. Insert the folded cup towards the position of your cervix rather than assuming it will be directly above the vaginal opening.

After the cup has opened, you may be able to slide a clean finger alongside it and check whether you can feel the cervix outside the rim. Only do this if it is comfortable and do not force your finger higher.

A cup does not have to remain low in the vagina. It may naturally settle higher and, for some people, the cervix sits partly inside the cup. This is usually not a problem if the cup is comfortable and is collecting your flow.

Our guide explains how to check your cervical position and how cervix height can affect cup length, capacity and removal.

The cup is full or overflowing

If leaking starts after several hours and the cup is full when you remove it, the most likely explanation is overflow rather than a poor seal.

The maximum wear time stated by the manufacturer is not a promise that the cup will hold your full flow for that long. On heavier days, you may need to empty it more frequently.

The cervix can also sit partly inside the cup and take up some of its usable capacity. This can make the cup overflow before it appears full to the rim. Do not force the cup to sit lower if that position is uncomfortable or does not suit your anatomy.

Instead, consider:

  • Emptying the cup more frequently on heavier days
  • Checking the cup’s usable capacity, usually measured to its air holes
  • Choosing a higher-capacity cup that still suits your cervix height and comfort
  • Trying a rounded or differently shaped cup that provides more capacity without excessive length

You can compare cup measurements and capacity using our menstrual cup comparison chart or explore menstrual cups for heavier periods.

Cup size, shape and firmness may be affecting the seal

If your cup is open and positioned around your cervix but continues to leak before it is full, its dimensions or design may not be providing a reliable fit.

A cup may leak because it is:

  • Too narrow: it may not feel stable or maintain consistent contact with the vaginal walls.
  • Too wide: it may remain compressed or struggle to open fully.
  • Too soft: it may be more likely to stay folded or become compressed during movement.
  • The wrong shape: a tapered, bell-shaped or rounded cup can sit differently even when the measurements are similar.
  • The wrong length: it may not sit comfortably in relation to your cervix or may be difficult to position and remove.

There is no universal menstrual cup sizing system. A small cup from one brand may be longer, wider or firmer than a regular cup from another.

Use our menstrual cup size guide, soft and firm cup guide and menstrual cup shape guide to understand how these features work together.

Why does my menstrual cup leak during exercise?

Running, jumping, lifting and other activities change pressure and movement through the abdomen and pelvic floor. A cup that works during ordinary daily activity may sometimes compress, shift or lose its seal during exercise.

Before exercising:

  • Empty the cup, particularly if your flow is heavy
  • Check that it has opened and is positioned around your cervix
  • Use backup protection if that helps you feel more confident

If exercise-related leaking continues, compare cups with a different firmness, shape or diameter. A firmer cup may resist compression more effectively for some people, but it may feel too noticeable for someone who is sensitive to pressure.

Leaking during exercise does not automatically mean that your pelvic floor is weak or that you need to start doing Kegel exercises. Pelvic floor function is more complex than “strong” or “weak”. Seek personalised advice from a pelvic health physiotherapist if leaking is accompanied by pelvic pressure, pain, bladder symptoms, a vaginal bulge or other concerns.

Check the air holes and condition of your cup

The air holes may be blocked

Many menstrual cups have small air or seal holes near the rim. The number and design vary between cups and some models do not have them.

Check any holes each time you clean the cup. If they are blocked, follow the manufacturer’s cleaning instructions. Flushing them with water, gently stretching the silicone around the hole or using a manufacturer-approved soft cleaning tool may help.

Do not use a sharp object, enlarge the holes or puncture the cup, as this could damage the material.

The cup may be worn or damaged

Inspect your cup regularly for tears, cracks, tackiness, loss of shape or other changes to its surface. A cup that no longer returns to its original shape may not open or seal as reliably as it once did.

Follow the manufacturer’s replacement guidance and read more about the lifespan of menstrual cups and discs.

When should you try a different cup or period product?

Menstrual cups can take some practice, but you do not have to persist indefinitely with a cup that repeatedly leaks, feels uncomfortable or is difficult to use.

Use the problem you are experiencing to guide your next choice:

  • If the cup repeatedly stays folded, compare diameter, shape and firmness.
  • If it leaks only when full, compare usable capacity or empty it more frequently.
  • If it shifts during movement, compare shape, diameter and firmness.
  • If your cervix takes up much of the cup, look for useful capacity in a shape and length that still fit comfortably.
  • If the cup causes pain or bladder pressure, stop using it and reassess the size, shape and firmness.

You can take our Find Your Best Fit Quiz for personalised starting suggestions or use the Menstrual Products Comparison Hub to compare cups, discs and other period care options.

A menstrual disc sits differently from a cup and may suit some people who have not found a comfortable or reliable cup fit. Disc fit still varies between individuals, so it is another option rather than a guaranteed solution.

When leaking may indicate heavy menstrual bleeding

A cup that fills rapidly is not always a product-fit problem. If your bleeding has become noticeably heavier or is affecting your daily life, speak with a healthcare professional.

Other signs of heavy menstrual bleeding can include:

  • Frequently bleeding through period products or clothing
  • Passing large blood clots
  • Bleeding for more than eight days
  • Needing to change period protection during the night
  • Feeling unusually tired, pale, dizzy or short of breath

Seek urgent medical help if you are bleeding very heavily and feel faint or think you may pass out.

The bottom line

The best way to troubleshoot a leaking menstrual cup is to look at when the leak occurs and what you find when you remove the cup.

A mostly empty cup suggests an opening or positioning issue. A full cup suggests overflow. Light spotting soon after insertion may simply be residual blood. Leaking during exercise or well before the cup is full may point towards a different diameter, shape or firmness.

There is no single cup or technique that works for every body. Use each attempt as information and choose the option that feels comfortable, manageable and reliable for you.

Related reading

This article provides general information and is not a substitute for individual medical advice. Speak with a qualified healthcare professional if you have symptoms or concerns about your health.

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