A menstrual cup is a small, flexible cup made from medical-grade silicone, latex rubber, or elastomer that you insert into your vagina to collect menstrual fluid. Unlike tampons, which absorb blood, a cup catches and holds it, with a capacity of 10 to 38 milliliters depending on the size. That’s roughly double what a tampon holds, which means less frequent changes throughout the day. Most cups can be worn for up to 12 hours before you need to empty them.
How a Menstrual Cup Works
You fold the cup, insert it into your vaginal canal, and let it pop open. Once inside, the cup creates a light seal against your vaginal walls, preventing leaks while fluid collects in the bell-shaped reservoir. When it’s time to empty, you pinch the base to release the seal, pull the cup out, pour the contents into the toilet, rinse, and reinsert.
Because cups collect rather than absorb, they don’t dry out your vaginal tissue the way tampons can. This makes them a popular choice for people with lighter flows or those who find tampons uncomfortable. In clinical studies, leakage rates with menstrual cups were similar to or lower than those of pads and tampons.
Choosing the Right Size
Most brands offer two or three sizes, and getting the right fit matters for both comfort and leak prevention. The main factors are your cervix height, pelvic floor strength, birth history, and flow volume.
Your cervix height determines how far up the cup will sit. To check, insert your longest finger into your vagina on or just before the first day of your period and feel for a smooth, slightly firm area at the top of the canal (it feels similar to the tip of your nose). If your finger goes all the way in before reaching it, you have a high cervix and may need a longer cup. If you reach it at the first knuckle, it’s low, and a shorter cup will work better. Anything in between is average.
Age, pregnancy, and vaginal birth can relax pelvic floor muscles over time. Many brands recommend smaller cups for people under 30 who haven’t given birth vaginally, and larger cups for those over 30 or who have delivered a baby. That said, if you’re physically active and have strong pelvic floor muscles, you may do fine with a smaller size regardless of age.
How to Insert and Remove
The key to insertion is folding the cup small enough to slide in comfortably. Three common folds work well:
- Punchdown fold: Push one side of the rim down into the cup’s base, creating a narrow tip. This is the easiest fold for beginners because the small insertion point slides in smoothly and the shape gives you a good grip.
- C-fold: Flatten the cup and fold it in half so the rim forms a C shape. It’s fast and simple but has a wider insertion point, so it works best once you’re comfortable with the process.
- 7-fold: Flatten the cup and fold one side of the rim diagonally down toward the base, forming a 7 shape. This creates an asymmetric tip that’s narrower than the C-fold.
Once the cup is inside, run a finger around the base to make sure it has fully opened. If it feels dented or folded, gently twist or press against the vaginal wall to let air in so the cup can expand.
To remove, bear down slightly with your pelvic muscles to bring the cup lower, then pinch the base firmly before pulling. Pinching breaks the seal, which is important. Pulling the stem alone without releasing that seal can feel uncomfortable and may cause a mess. With a little practice, the whole process takes about the same time as changing a tampon.
Cleaning and Maintenance
During your period, rinse the cup with warm water each time you empty it. Plain, unscented soap is fine if you want a deeper clean between empties. At the end of your cycle, sterilize the cup by placing it in boiling water for up to 10 minutes. Having a second cup lets you alternate, so one can be sterilized while you use the other.
Certain products can degrade the silicone or irritate vaginal tissue. Avoid antibacterial soap, oil-based soap, scented soap, baking soda, bleach, dishwashing liquid, hydrogen peroxide, rubbing alcohol, and vinegar. Store the cup in a breathable cloth bag between cycles, not in an airtight container where moisture could promote bacterial growth.
Safety and Infection Risk
Menstrual cups carry a very low risk of toxic shock syndrome (TSS), the same rare but serious bacterial infection historically associated with tampon use. At least one case of TSS in a menstrual cup user has been documented, so the risk isn’t zero, but it remains extremely uncommon. The practical ways to minimize risk are the same as with any internal menstrual product: empty on schedule, wash your hands before insertion and removal, and sterilize the cup between cycles by boiling.
Using a smaller cup when your flow allows it may also help, since a larger cup can create more space for bacterial growth. On heavier days, empty more frequently rather than relying on the full 12-hour window.
Menstrual Cups and IUDs
If you have an IUD, menstrual cups deserve some extra caution. A 2024 study published in the journal Contraception tracked over 1,000 copper IUD users over three years. Among those who used menstrual cups, 6.8% experienced a complete spontaneous expulsion of their IUD, compared to 2.9% of those who didn’t use cups. Accidental self-removal (pulling the IUD out along with the cup) was even more notable: 9.2% among cup users versus just 0.9% among non-users.
This doesn’t mean you can’t use a cup with an IUD, but it does mean you should be careful to break the seal before removing the cup and avoid tugging on your IUD strings. Some people find it helpful to have their provider trim the strings shorter after insertion.
Cost and Environmental Impact
A single menstrual cup typically costs between $20 and $40 and lasts several years with proper care. Compare that to a recurring monthly expense for tampons or pads, and most people recoup the cost within a few cycles. The environmental math is similarly straightforward: one reusable cup replaces thousands of disposable products over its lifespan, keeping a significant amount of plastic and cotton out of landfills.
Who Menstrual Cups Work Best For
Cups are a good fit for most people who menstruate, including teenagers, though comfort with insertion is a real factor. If you’re not yet comfortable using tampons, you may want to start there first. People with certain pelvic conditions, such as prolapse or vaginismus, may find cups difficult or painful to use. And as noted above, IUD users should weigh the slightly elevated risk of displacement.
The learning curve is real. Most people need two or three cycles to get consistently comfortable with folding, positioning, and removal. Leaks during that adjustment period are common, so wearing a backup liner for the first few cycles is a practical move.