Keshavarzi F, et al. - Researchers investigated whether and if so to what extent melatonin and meloxicam can improve subjective and objective sleep and reduce pain among women with primary dysmenorrhea (PD). They conducted a double-blind cross-over clinical trial lasting for three menstrual cycles. During the second and third menstruations, subjective sleep improved and pain decreased irrespective of whether melatonin or meloxicam was administered first or second. In a similar manner, objective sleep efficiency increased and objective sleep latency shortened. Compared to meloxicam, melatonin proved more efficacious. Results suggest that among women with primary dysmenorrhea, both melatonin and meloxicam are suitable to treat pain and PD-related sleep complaints.