BackgroundMenstrual cups offer a cost‐effective and environmentally sustainable product for many young people. While clinical trials have shown their safety and effectiveness, no studies have investigated their performance in real‐world use.AimsTo describe the acceptability and functionality (continuation, discomforts, leakage, and adverse events) of menstrual cups and investigate the supportive role of product knowledge.Materials and MethodsA cross‐sectional online survey of 530 people aged 15–24 living in Australia who had ever used a menstrual cup, recruited via a menstrual cycle tracking application.ResultsMore than half of participants (55%) were still using their first menstrual cup at the time of the survey, 16% had switched to an alternative cup, and 29% had discontinued use. In their first cycle of use, 54% of participants reported leakage and 25% reported pain or discomfort with the cup in place. Many participants (45%) reported being unable to remove the cup on their first attempt, with subsequently 17% requiring help to remove it, and 2% reported displacement of an intra‐uterine device during removal. These figures decreased for subsequent cycles. Half of the participants were aware prior to using a cup that different cup models may offer a better fit for different individuals. This knowledge was associated with decreased odds of needing help to remove the cup (adjusted odds ratio 0.57, 95% CI 0.35–0.94) or discontinuing use (adjusted relative risk ratio 0.66, 95% CI 0.44–1.00).ConclusionsDifficulties using menstrual cups are common in real‐world use and higher than reported in clinical trials. Improved education provision may support more positive user experiences.