RecruitingPhase 3Drug trialEvaluation of the Analgesic Effect of Intramyometrial Botulinum Toxin Injection Via Hysteroscopy in Severe Primary DysmenorrheaThe objective of the study is to evaluate the global impression of improvement at 3 months following intramyometrial botulinum toxin injections via hysteroscopy in women with severe primary dysmenorrhea who have failed first-line medical treatment, compared to intramyometrial placebo injections.