Overview Viagra in the Treatment of Primary Dysmenorrhea Status: Completed Trial end date: 2011-08-01 Target enrollment: Participant gender: Summary The primary hypothesis is that a 100mg single dose of sildenafil citrate (Viagra) will have a higher improvement rate when compared to placebo in the treatment of moderate to severe primary dysmenorrhea. Phase: Phase 1/Phase 2 Details Lead Sponsor: Milton S. Hershey Medical CenterCollaborator: National Institutes of Health (NIH)Treatments: Citric AcidSildenafil Citrate