A menstrual cup is a reusable feminine hygiene product, typically made of medical-grade silicone, rubber, or TPE, which is folded and inserted into the vagina to collect menstrual fluid. Once inside, it unfolds to create a seal against the vaginal walls, providing up to 12 hours of leak-free protection. Because the cup forms this seal and is removed by the user’s action, a common concern arises about whether this suction or the removal process could negatively affect the body’s supporting structures. The central question is whether this alternative poses a risk to the pelvic floor muscles.
The Role and Structure of the Pelvic Floor
The pelvic floor is a hammock-like group of muscles and connective tissues located at the base of the pelvis, spanning from the pubic bone to the tailbone. These muscles support internal organs, including the bladder, uterus, and rectum, keeping them in their proper positions. Their functions are integral to maintaining urinary and fecal continence, stabilizing the core, and supporting sexual function.
The vaginal canal passes directly through this muscle layer. When a menstrual cup is inserted, it sits low in the vaginal canal, relying on the tone of these muscles to keep it sealed and correctly positioned. The strength and flexibility of the pelvic floor muscles are directly related to a user’s comfort and the cup’s performance.
Current Evidence on Cups and Pelvic Health
Medical and scientific literature does not establish a direct causal link between the correct use of a menstrual cup and pelvic floor dysfunction. Concerns, such as the cup causing or worsening pelvic organ prolapse (POP), are considered theoretical or anecdotal. POP is a condition where organs like the uterus or bladder descend into the vaginal canal, typically caused by factors like childbirth, chronic straining, age, and genetics.
Existing medical literature and expert consensus do not recognize a connection between menstrual cup use and POP. The risk is primarily linked to improper removal, specifically when a user repeatedly pulls on the cup without breaking the suction seal. Small studies suggest no negative impact on muscle function. Gynecologists advise that when used correctly, the menstrual cup is a safe product that does not weaken the supportive pelvic structures.
Understanding Suction and Proper Removal Techniques
The suction seal prevents leaks, but it must be released before the cup is removed to avoid placing strain on the pelvic tissues. The vacuum forms when the cup opens inside the vagina, creating a pressure differential that holds it securely against the walls. Pulling the cup out by the stem while the seal is intact can tug on the delicate tissues of the vaginal wall and potentially the cervix.
To ensure safety, the seal must be broken before removal. This is achieved by inserting a finger alongside the cup and gently pinching the base or pressing on the side of the rim. This action allows air to enter and equalize the pressure, releasing the suction. Only after the seal is broken should the cup be gently pulled out by grasping the base, not the thin stem, which is only meant as a guide. Bearing down with the pelvic muscles to push the cup lower is an accepted technique for reaching the base, but this should be gentle and brief, avoiding repeated straining, which can increase intra-abdominal pressure.
Selecting the Right Cup for Pelvic Safety
Choosing the right cup minimizes potential risk and maximizes comfort. Cup size is typically determined by factors like age, childbirth history, and flow intensity, but pelvic floor muscle tone is also a consideration.
Individuals with strong pelvic floor muscles, often due to regular exercise or no history of vaginal delivery, may find a smaller or firmer cup is necessary to prevent it from being crushed or shifting. Conversely, a softer or slightly larger diameter cup may be recommended for those with weaker pelvic floor tone, such as after vaginal childbirth, to ensure a reliable seal.
Cup firmness is a direct factor in comfort and function. An overly stiff cup can press uncomfortably against the vaginal walls or bladder. Selecting a softer, more flexible cup is a better choice for individuals with a sensitive bladder or a history of pelvic discomfort to reduce internal pressure.