A menstrual cup is a menstrual hygiene device which is inserted into the vagina during menstruation. Its purpose is to collect menstrual fluid (blood from the uterine lining mixed with other fluids). Menstrual cups are usually made of flexible medical grade silicone, latex, or a thermoplastic isomer. They are impermeable and collect menstrual fluid, unlike tampons and menstrual pads, which absorb the fluid instead.

Menstrual cups come in two types. The older type is bell-shaped, often with a stem or a ring, and has walls more than 2mm thick. The second type is bowl-shaped, roughly hemispherical, and apart from the springy rim, has thin, flexible walls. Thick-walled cups sit over the cervix, like cervical caps, but they are generally larger than cervical caps and cannot be worn during vaginal sex. Thin-walled cups sit in the same position as a contraceptive diaphragm; they do not block the vagina and can be worn during vaginal sex. Menstrual cups are not meant to prevent pregnancy.

Every 4–12 hours (depending on capacity and the amount of flow), the cup is emptied (usually removed, rinsed, and reinserted). After each period, the cup requires cleaning. One cup may be reusable for up to 10 years, making their long-term cost lower than that of disposable tampons or pads, though the initial cost is higher. As menstrual cups are reusable, they generate less solid waste than tampons and pads, both from the products themselves and from their packaging. Thick-walled cups have to fit fairly precisely; it is common for users to get a perfect fit from the second cup they buy, by judging the misfit of the first cup. Thin-walled cups are one-size-fits-most, but some manufacturers sell multiple sizes. Some menstrual cups are sold colorless and translucent, but several brands also offer colored cups.

Reported leakage for menstrual cups is similar or rarer than for tampons and pads. Incorrect placement or cup size can cause leakage. Menstrual cups are a safe alternative to other menstrual products; risk of toxic shock syndrome infection is similar or lower with menstrual cups than for pads or tampons.

Terminology[edit]

The terminology used for menstrual cups is sometimes inconsistent. This article uses "menstrual cup" to mean all types, and for clarity, distinguishes the two main types by wall thickness. The thick-walled cups are bell-shaped, and look like contraceptive cervical caps; the thin-walled cups are bowl-shaped, and look like contraceptive diaphragms.

Regulation generally does not distinguish the two types. The US Food and Drug Administration holds that "A menstrual cup is a receptacle placed in the vagina to collect menstrual flow." The EU legislated that "The product group ‘reusable menstrual cups’ shall comprise reusable flexible cups or barriers worn inside the body whose function is to retain and collect menstrual fluid, and which are made of silicone or other elastomers."

Because thick-walled cups are commonly depicted as being placed in the vaginal canal, well below the cervix, they are also called "vaginal cups", with the thin-walled cups called "cervical cups". MRI imaging suggests that, contrary to some manufacturer's depictions, thick-walled cups are placed over the cervix, in a position similar to a cervical cap (not to be confused with a cervical cup). Thin-walled "cervical cups" also cover the cervix, but have one edge located further down the vagina. Thin-walled cups are also called "menstrual discs", distinguishing them from "menstrual cups" in the narrower sense.

In the 1800s, menstrual cups were called "'catamenial sacks", and were similar external catamenial sacks of "canoe-like form" , which in turn were similar to catamenial sacks which were waterproof rubber undersheet supports for absorbant pads. These were made from india-rubber or gutta-percha, forms of latex.

Use[edit]

Menstrual cups are favoured by backpackers and other travellers, as they are easy to pack and only one is needed.

Insertion[edit]

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