NCT07508358

Vaginal Sildenafil for Primary Dysmenorrhea

Vaginal Sildenafil for Primary Dysmenorrhea: A Randomized, Double-Blind, Placebo-Controlled, Two-Period Crossover Mechanistic Study

• Status: Not Yet Recruiting
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 50 (estimated)
• Sponsor: Kevin Hellman · Academic / Other
• Sex: Female
• Age: 18 Years – 35 Years
• Healthy volunteers: Not accepted

Summary

This phase 1 randomized, double-blind, placebo-controlled, two-period crossover trial will evaluate whether a single 100 mg vaginal sildenafil citrate suppository reduces uterine hypercontractility during menstruation in adults with moderate-to-severe dysmenorrhea. Uterine contractility will be measured using cine magnetic resonance imaging (MRI). Key secondary objectives are to evaluate acute menstrual pain reduction over 4 hours, characterize limited systemic exposure using a single 4-hour plasma sildenafil concentration, and assess short-term safety and tolerability.

Detailed description

Dysmenorrhea is believed to be driven in part by excessive uterine contractility. Sildenafil, a phosphodiesterase-5 inhibitor, may reduce myometrial hypercontractility through enhanced nitric oxide-cGMP signaling. Prior vaginal sildenafil data suggested acute pain relief, but mechanism and systemic exposure were not well characterized. This mechanistic target-engagement study uses a randomized, double-blind, placebo-controlled, two-period crossover design. Participants will complete a screening visit and two menstrual treatment visits during separate cycles. At each treatment visit, participants with active menstrual pain will undergo baseline MRI, self-administer either vaginal sildenafil citrate 100 mg or matching placebo, and then complete repeat MRI assessments approximately 2 and 4 hours after dosing. Pain ratings, vital signs, adverse event assessments, pregnancy testing, and a single 4-hour blood draw for plasma sildenafil concentration will be obtained. Menstrual effluent samples will also be collected. The primary objective is to determine whether vaginal sildenafil produces measurable reductions in uterine hypercontractility during menstruation. Secondary objectives are to evaluate the effect of treatment on menstrual pain intensity over the 4-hour observation window, assess systemic exposure after vaginal administration, and characterize short-term hemodynamic and clinical tolerability.

Conditions

• Dysmenorrhea
• Menstrual Pain

Interventions

Type	Name	Description
DRUG	Sildenafil citrate vaginal suppository	A single 100 mg vaginal sildenafil citrate suppository compounded in an emulsifying MBK base is administered during one treatment period of the crossover study.
DRUG	Placebo vaginal suppository	A single matched placebo vaginal suppository without active sildenafil is administered during one treatment period of the crossover study.

Timeline

• Start date: 2026-05-01
• Primary completion: 2027-05-01
• Completion: 2027-10-01
• First posted: 2026-04-02
• Last updated: 2026-04-02

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study