A menstrual disc is a flexible, shallow collection device that sits in the widest part of the vaginal canal, called the fornix, just below the cervix. Instead of absorbing menstrual blood like a tampon, it catches and holds fluid in a soft basin. Most discs can be worn for up to 12 hours and hold significantly more fluid than tampons or even menstrual cups.
How a Menstrual Disc Works
The vaginal canal is relatively narrow, but it opens into a wider space near the cervix called the vaginal fornix. A menstrual disc sits in this wider area, with its rim tucked up behind the pubic bone on one side and nestled around the back of the cervix on the other. That pubic bone acts like a shelf, holding the disc in place through gentle tension rather than suction. This is the key difference from a menstrual cup, which creates a seal against the vaginal walls lower in the canal.
Because the disc doesn’t rely on suction, many people find it more comfortable, especially those with sensitive vaginal walls. The disc essentially surrounds the cervix and catches fluid as it exits, collecting it in the shallow bowl of the device.
Disc vs. Cup: The Key Differences
Menstrual cups and discs are both internal, reusable period products, but they work differently and sit in different locations. A cup is bell-shaped, sits in the lower vaginal canal, and stays in place by creating a gentle suction seal against the vaginal walls. A disc is flatter and wider, sits higher up in the fornix, and is held by tension against the pubic bone with no suction involved.
This distinction matters in a few practical ways. The lack of suction makes discs easier to remove for some people and potentially more comfortable during long wear. It also means discs can be worn during penetrative sex, since they sit high enough in the fornix to leave the vaginal canal mostly unobstructed. Cups sit too low for this and need to be removed before intercourse.
Capacity Compared to Other Products
Menstrual discs hold more fluid than any other common period product. A 2024 study published in BMJ Sexual & Reproductive Health tested the red blood cell capacity of various products and found that discs averaged 61 mL, with the highest-capacity disc holding 80 mL. For comparison, a regular tampon holds about 20 mL, a heavy-absorbency tampon around 31 to 34 mL, and most menstrual cups fall in the 20 to 50 mL range.
That higher capacity makes discs particularly appealing for people with heavy periods. Even on a heavy flow day, a disc may last the full 12 hours without needing to be emptied, though individual experience varies.
Materials and Sizing
Reusable menstrual discs are typically made from 100% medical-grade silicone. They’re free of BPA, latex, and common toxins, and most are FDA registered. A single reusable disc can last for years, making it both cost-effective and lower-waste than disposable options. Disposable discs also exist, usually made from a flexible polymer with a thin collection film, designed to be thrown away after a single use.
Most discs come in one or two sizes. A common diameter is around 68 mm, which fits the majority of bodies. Some brands offer a smaller and larger option to account for differences in anatomy, particularly variations in fornix width and pubic bone position. If a disc feels like it’s slipping or pressing uncomfortably, trying a different size usually solves the problem.
How to Insert and Remove a Disc
To insert a menstrual disc, you pinch the rim so it narrows into an elongated shape, similar to pinching a hot dog bun. Slide it back along the vaginal canal, angled slightly downward toward the tailbone. Once the back edge passes the cervix, tuck the front rim up behind the pubic bone. You should be able to feel it locked into place, and it shouldn’t feel like it’s sliding down.
Removal requires hooking the front rim with a finger. Most people use an index finger or thumb in a “come hither” motion to hook under or over the front edge of the rim, then pull forward gently. Once the rim is close to the vaginal opening, pinching it between a finger and thumb gives better control and helps keep the disc level so fluid doesn’t spill. Removal can be messier than a cup, especially while you’re still learning. Doing it over the toilet or in the shower helps.
Auto-Dumping: Emptying Without Removal
One feature unique to menstrual discs is auto-dumping. When you contract your pelvic floor muscles, like the bearing-down motion you’d use on the toilet, the disc tilts slightly forward and allows collected fluid to flow out. Once you relax the muscles, the disc settles back into position on its own.
This means you can partially empty your disc every time you use the bathroom without ever taking it out. For people with heavier flows, auto-dumping extends wear time significantly. It’s not something you have to do; it happens naturally for many disc users when they sit on the toilet and use those muscles. Some people find it happens unintentionally during exercise or certain movements, which can cause minor spotting. A pantyliner handles this easily if it’s a concern.
Wearing a Disc During Sex
Because a menstrual disc sits high in the vaginal fornix and leaves the vaginal canal relatively clear, many discs can be worn during penetrative intercourse. This is one of the most common reasons people choose a disc over a cup. The disc collects menstrual fluid at the cervix, so both partners typically can’t feel it, and it keeps things mess-free.
Not every disc is designed for this, so checking the product’s guidelines matters. Firmer rims are generally more likely to be noticeable during sex, while softer, thinner discs tend to go undetected. It’s worth a comfort test before relying on it in the moment.
Safety and Infection Risk
Menstrual discs carry a similar safety profile to cups and modern tampons. Toxic shock syndrome, the infection historically linked to high-absorbency tampons, is rare with any current menstrual product. TSS is caused by toxin-producing bacteria and was largely addressed in the 1980s when tampon materials were reformulated. Because discs collect rather than absorb fluid, they don’t create the same drying environment that contributed to TSS risk with older tampon designs.
The main hygiene consideration is the same as with any internal product: wash your hands before insertion and removal, clean reusable discs between uses with mild soap and water, and sterilize them by boiling between cycles. Wearing any internal product for longer than 12 hours increases infection risk, so sticking to that window is a reasonable guideline.
IUD Compatibility
One concern for IUD users is whether an internal period product could dislodge their device. Menstrual cups have raised this question because their suction seal could theoretically pull on an IUD during removal. Discs don’t use suction, which in theory reduces that risk. Still, if you have an IUD, it’s worth being mindful during removal. Hooking the rim carefully and avoiding pulling on IUD strings reduces any chance of displacement.