The Complete Handbook of Menstrual Cups

Chapter 1: Understanding Menstrual Cups

A menstrual cup is a reusable, internal feminine hygiene device that collects menstrual fluid rather than absorbing it. That core difference - collection versus absorption - drives every practical advantage and every operational consideration discussed in this handbook. Unlike a tampon or pad, which wicks and holds fluid, a cup forms a mechanical seal against the vaginal walls and holds fluid in a reservoir until you remove and empty it. This is not a cosmetic variation on an existing idea. It is a different class of device with different physics, different maintenance requirements, and different failure modes.

The device itself is typically a bell-shaped or thimble-shaped vessel made of medical-grade silicone, thermoplastic elastomer (TPE), or natural rubber latex. It has two structural elements that matter: the rim and the stem. The rim is the stiffened upper edge that creates the seal against the vaginal wall. The stem is a small tab or rod at the bottom of the cup, used for positioning and removal. Between the rim and the stem sits the body, which is the flexible reservoir that holds the fluid. Most cups range from 40 to 50 millimeters in length and hold between 20 and 40 milliliters of fluid, although some extended-size models hold up to 50 milliliters. For reference, a regular tampon holds about 5 to 10 milliliters when fully saturated. That capacity difference is not a minor detail; it is the primary reason a cup can be worn for 8 to