Menstrual cup pain almost always traces back to a mismatch between the cup and your body, not a problem with cups in general. The most common culprits are a cup that is too firm or too large for your anatomy, incorrect positioning relative to your cervix, and the suction seal the cup forms inside the vaginal canal. In one prospective study, most participants who experienced discomfort found it resolved after the first menstrual cycle of use, while a smaller number had ongoing issues that pointed to fit or technique problems.1Taylor & Francis Online (Women’s Health). The influence of the menstrual cup on female pelvic floor muscles variables: a prospective case series The good news is that nearly every source of cup-related pain has a fix.
The Learning Curve Is Real
If you just started using a menstrual cup and it hurts, that is extremely common and does not mean cups are wrong for you. In a study tracking new cup users over several cycles, seven out of ten women who reported discomfort experienced it only during the first cycle. By the second or third cycle, they had adjusted their insertion angle, figured out how to position the cup relative to their cervix, and the pain stopped.1Taylor & Francis Online (Women’s Health). The influence of the menstrual cup on female pelvic floor muscles variables: a prospective case series Three out of the ten, however, had discomfort throughout the study, suggesting their issue was more about cup characteristics than technique.
The first-cycle learning curve involves a few things at once. You are learning to fold the cup in a way that makes insertion comfortable, finding the depth at which it sits without pressing on sensitive structures, and getting used to the sensation of breaking the seal before removal. Rushing any of those steps, especially removal, is what turns mild awkwardness into actual pain.
The Cup Is Too Firm or Too Large
Menstrual cups vary enormously in diameter, length, rim thickness, and silicone firmness. A cup that works perfectly for one person can cause cramping, pressure, or a persistent ache for someone else, and the reason usually comes down to those physical properties. A firmer cup pushes outward against the vaginal walls with more force, which can press on the bladder anteriorly or the rectum posteriorly. A cup that is too long can bump against the cervix or sit partially outside the vaginal opening, both of which hurt.
Research comparing menstrual cups has highlighted that these physical differences in diameter, body stiffness, and rim design directly affect comfort and are linked to user complaints of pain and leaking.2PubMed Central. Comparison between menstrual cups: first step to categorization and improved safety Unfortunately, there is no industry-wide sizing standard. A “size small” from one brand can be wider or firmer than a “size large” from another. Most brands base their size recommendations on age and whether you have given birth vaginally, but those two factors alone do not capture the variation in vaginal length, cervix height, or pelvic floor tone that actually determines whether a cup fits comfortably.
If your cup causes a dull ache or a feeling of pressure against your bladder, try a softer cup. If it feels like it is sitting too low or poking out, you likely need a shorter cup or one designed for a low cervix. If you feel cramping similar to period cramps but worse than usual, the cup may be too firm and is pressing your vaginal walls outward enough to irritate the uterus or surrounding muscles.
Suction and Pressure Pain
The seal a menstrual cup creates is essential to how it works. The rim opens fully inside the vaginal canal, forming a light suction against the vaginal walls that keeps the cup in place and prevents leaks. But that same suction can cause pain in two distinct ways.
First, if the cup creates too strong a vacuum, you can feel a pulling or tugging sensation, particularly on your cervix. This is more common with firmer cups that spring open aggressively. The negative pressure inside the cup is real and measurable. A review of menstrual cup biomechanics found that cups generate meaningful negative pressure within the vaginal canal, which can exert upward force on internal structures.3International Journal of Research in Medical Sciences. Biomechanics and suction force of menstrual cups: implications for IUD users That force is usually mild enough to go unnoticed, but with a stiff cup or certain anatomical configurations, you feel it as cramping or a dragging sensation.
Second, and more dramatically, removal without breaking the seal first can cause sharp pain. Pulling a cup straight down without pinching the base to release the vacuum is like trying to pull a suction cup off a smooth surface. The vacuum resists, and the rim drags against the vaginal walls and cervix on the way out. The fix is straightforward: always pinch the base of the cup or press one side of the rim inward to let air in before you pull downward. Some people find it easier to bear down slightly with their pelvic floor muscles to move the cup lower before reaching the base.
Cervix Position Matters More Than You Think
Your cervix is the lower tip of the uterus, and it protrudes slightly into the upper vagina. Its position varies from person to person and even shifts during your cycle, sitting lower during menstruation for many people. A cup that bumps directly against the cervix or, worse, sits beside it rather than around it, will hurt.
When the cup sits beside the cervix instead of cradling it, the cervix is outside the collection area. Blood leaks past the cup, and the rim presses against the cervix from the side, which often feels like sharp, localized pain or cramping that gets worse as the cup fills. The solution is to check your cervix height before buying a cup. You can do this by inserting a clean finger during your period and noting how far in you can reach before touching the cervix. If you can barely insert a finger before reaching it, you have a low cervix and need a short, wide cup. If you cannot reach it easily, a longer cup is fine.
After inserting the cup, run a finger around the rim to confirm the cervix is inside the cup, not beside it. This single check prevents both leaking and the specific pain caused by cervix contact with the rim.
Bladder Pressure and Urinary Symptoms
The vagina and bladder are separated by a thin, flexible wall, which is why a menstrual cup that presses forward can affect urination. Many cup users report a feeling of needing to urinate more often, a weak urine stream, or a sense of incomplete emptying while the cup is in place. In most cases this is mild and resolves when the cup is removed.
In rare instances, however, the pressure can become serious. A case report documented a young woman who developed acute urinary retention from her menstrual cup. The anatomical proximity of the bladder and ureters, combined with the thinness of the vaginal wall, allowed the cup to compress the urethra and bladder neck. A concurrent urinary tract infection made the situation worse, and she was unable to urinate until the cup was removed and the infection treated.4Acta Urológica Portuguesa. Acute Urinary Retention and Menstrual Cup Use: Case Report
This is an extreme case, not a common outcome. A safety assessment of a medical-grade silicone menstrual cup found that post-void residual urine volume was similar with and without the cup in place, and self-reported comfort measures showed no significant difference between conditions.5PubMed Central. Safety assessment scheme for menstrual cups and application for the evaluation of a menstrual cup comprised of medical grade silicone But if you notice you cannot fully empty your bladder while wearing a cup, switching to a softer or narrower model usually resolves it. If you develop an inability to urinate at all, remove the cup immediately and seek medical attention.
Pelvic Floor Tension and Sensitivity
Some people experience cup-related pain that does not correspond neatly to sizing or positioning. It feels more like a general soreness or tightness in the vaginal area, particularly during insertion and removal. This often points to pelvic floor muscle tension rather than a cup problem per se.
A scoping review of pelvic floor outcomes associated with menstrual cup use found that reported symptoms included pain, initial vaginal discomfort, and changes in pelvic floor symptom burden, though the evidence was too varied to establish a direct causal link between cup use and pelvic floor dysfunction.6SpringerLink / International Urogynecological Journal. Pelvic Floor-Related and Genitourinary Outcomes Associated with Menstrual Cup Use: A Scoping Review In other words, researchers have documented these complaints but cannot yet say whether the cup causes pelvic floor problems or whether people with pre-existing pelvic floor tension simply have a harder time with cups.
If you suspect pelvic floor tension is the issue, there are a few things to try. Inserting the cup while in a squatting position or with one foot elevated on the edge of a bathtub can help relax the pelvic floor muscles. Using a water-based lubricant on the rim makes a significant difference for people whose pain is concentrated at the moment of insertion. And if you have other symptoms of pelvic floor dysfunction, like pain during sex, difficulty with tampons, or chronic pelvic pain outside your period, a pelvic floor physical therapist can help you address the underlying tension, which will make cup use easier as a secondary benefit.
Insertion and Removal Technique
Technique problems are the most fixable cause of cup pain, and they account for a large share of first-cycle complaints. A few specific mistakes come up repeatedly.
- Wrong fold: The classic C-fold creates the widest insertion point. If that hurts, try a punch-down fold or a seven-fold, both of which create a narrower tip that opens more gradually once inside.
- Too shallow placement: If the cup sits too low, the stem pokes the vaginal opening and the rim does not seal properly. Push it up until the base sits comfortably past the pubic bone.
- Yanking on removal: Pulling the stem without breaking the seal first causes a sharp vacuum pain. Pinch the base, let air in, then ease the cup out at a slight angle.
- Tensing up: Anxiety about insertion, especially for new users, causes the pelvic floor to clench. This narrows the vaginal canal and makes the cup harder to insert, which causes more anxiety. Breathing out slowly during insertion and trying different positions can break this cycle.
Most experienced cup users settle into a routine within two or three cycles. If pain persists beyond that despite trying different folds and positions, the cup itself is likely the wrong size or firmness for your body rather than a technique issue.
When You Also Use an IUD
If you use a menstrual cup alongside an intrauterine device, pain during cup removal deserves special attention because of what it might mean for your IUD. A systematic review found a possible association between menstrual cup use and increased risk of IUD expulsion.7PubMed Central. Menstrual cup and risk of IUD expulsion – a systematic review A case series documented seven instances where IUD expulsion occurred during concurrent menstrual cup use, though the exact mechanisms were unclear.8PubMed. Unintentional IUD expulsion with concomitant menstrual cup use: a case series
More detailed data came from a randomized trial of copper IUDs. Among cup users, about 16% experienced IUD expulsion within 12 months, compared to 5% among non-users. By 36 months, the gap widened to roughly 23% versus 9%. Cup users also had significantly higher rates of accidental self-removal of their IUD, meaning they inadvertently pulled the IUD out while removing the cup.9PubMed Central. Menstrual cup use and intrauterine device expulsion in a copper intrauterine device randomized trial The suction forces generated during cup removal appear to be the primary mechanism: if the IUD strings get caught between the cup rim and the vaginal wall, or if the vacuum tugs upward on the IUD, the device can shift or come out entirely.3International Journal of Research in Medical Sciences. Biomechanics and suction force of menstrual cups: implications for IUD users
This does not mean you cannot use both. But if you do, always break the suction completely before removal, and tuck your IUD strings out of the way of the cup rim after insertion. If you feel unusual cramping or a sharp pain when removing your cup, check that your IUD strings are still in place. Pain during cup removal in IUD users is worth mentioning to your healthcare provider, because it could signal the IUD has partially dislodged.
When the Cup Itself Is Not the Problem
Occasionally, what seems like cup pain is actually an underlying condition that the cup makes more noticeable. Endometriosis, adenomyosis, and vulvodynia can all cause pain that worsens with any vaginal insertion. Vaginismus, a condition where the vaginal muscles involuntarily tighten, can make cup insertion painful or impossible. If you have tried multiple cup sizes, softness levels, and techniques and still find insertion or wear painful, it is worth talking to a gynecologist about whether something else is going on.
Infections are another consideration. A cup should not cause an infection on its own if properly cleaned, and safety testing of medical-grade silicone cups has found no significant changes in vaginal pH and no increase in burning, itching, or stinging compared to baseline.5PubMed Central. Safety assessment scheme for menstrual cups and application for the evaluation of a menstrual cup comprised of medical grade silicone But if you develop new pain along with unusual discharge, odor, or burning that persists after removing the cup, a vaginal infection such as bacterial vaginosis or a yeast infection may have developed independently, and the cup’s presence can make the symptoms feel worse.
Choosing a Different Cup
If your current cup hurts and technique adjustments have not helped, switching cups is the most productive next step. Here is a practical framework for narrowing down what to try.
- Pressure or bladder symptoms: Go softer. A cup with a lower firmness rating puts less outward force on the vaginal walls and is less likely to press on the bladder or urethra.
- Cramping or dragging sensation: Go softer and possibly smaller in diameter. The cramping is likely from the cup pushing your vaginal walls outward enough to affect the uterus or pelvic floor muscles.
- Cervix pain or one-sided sharp pain: Reassess your cervix height and switch to a cup designed for your cervix position. A low-cervix cup is shorter with a wider bowl; a high-cervix cup is longer and narrower.
- Pain at the vaginal opening: Check that the cup is sitting high enough. If it is, trim the stem or choose a cup with a flush or ring-style grip. Some stems are rigid enough to poke sensitive tissue near the opening.
- Insertion pain specifically: Try a lubricant on the rim, a narrower fold, and a cup with a smoother, thinner rim. Cups with a thick, pronounced rim are harder to insert comfortably.
Because there is no universal sizing standard across brands, community-maintained comparison charts that list actual measured dimensions, firmness ratings, and capacity can be more helpful than the size guides on any individual brand’s website.2PubMed Central. Comparison between menstrual cups: first step to categorization and improved safety Researchers have called for better transparency and standardized labeling so that consumers can make informed comparisons. Until that happens, independent user databases remain the most practical tool for finding a cup that matches your anatomy.
Menstrual Discs as an Alternative
If cups continue to cause pain despite trying different sizes and brands, menstrual discs are worth considering. Discs sit in a different position: they tuck behind the pubic bone and cover the cervix from below, rather than sitting lower in the vaginal canal like a cup. Because of this placement, they put less outward pressure on the vaginal walls and do not rely on the same degree of suction to stay in place.
Discs are not universally better. Some people find them harder to insert and remove, and they can be messier. They also come in fewer size and firmness variations than cups currently do. But for someone whose cup pain stems from bladder pressure, pelvic floor tension, or sensitivity to suction, the different mechanics of a disc may eliminate the problem entirely. They are also a reasonable option for IUD users who want to avoid the suction-related risks associated with cup removal.
Neither cups nor discs are inherently superior. They work differently and suit different anatomies. If one category is painful for you, it is worth trying the other before concluding that internal period products are off the table.