Effect of long-term intranasal oxytocin on sexual dysfunction in premenopausal and postmenopausal women: a randomized trial

Objective To assess the effect of on-demand intranasal oxytocin administration on female sexual function and activity. Design Randomized, prospective, double-blind, placebo-controlled, crossover trial with duration of 22 weeks. Setting Academic medical center. Patient(s) Thirty pre-and postmenopausal women with sexual dysfunction. Intervention(s) Over 8 weeks, intranasal oxytocin (32 IU) or placebo self-administered by women within 50 minutes before sexual intercourse; after a washout period of 2 weeks, crossover with patients switched to the alternate group for another 8 weeks. Main Outcome Measure(s) Primary outcome parameter: Female Sexual Function Index (FSFI); secondary outcome parameters: Female Sexual Distress Scale (FSDS), Sexual Quality of Life–Female (SQOL-F), Sexual Interest and Desire Inventory–Female (SIDI-F), and Hamilton depression scale (HDS). Result(s) After oxytocin and placebo, the FSFI score increased by 26% and 31%, SQOL-F score by 144% and 125%, and SIDI-F score by 29% and 23%, respectively (repeated measures analysis of variance between groups). After oxytocin and placebo, the FSDS score decreased by 36% and 45%, respectively (repeated measures analysis of variance between groups). There was no statistically significant treatment, sequence (placebo first/second), or interaction effect. Conclusion(s) Long-term intranasal oxytocin and placebo administration both improved sexual function and symptoms of depression in women over time with no treatment, sequence (placebo first/second), or interaction effect. Clinical Trial Registration Number NCT02229721.