Effects of NLS-133, a Potential Non-Hormonal "On-Demand" Male Contraceptive

NLS-133-CLIN001 is a Phase 2a study designed to assess the safety, tolerability, and effects of NLS-133 (combination of two FDA-approved agents) compared to an active control (FDA-approved pharmacologic agent) or placebo on semen volume and sperm count in 10 in healthy men. Participants will be randomized in a crossover design to receive a single dose of NLS-133, an active control or placebo either 90 or 180 minutes prior to collection of semen. Sperm parameters measured will be count, motility and morphology. A brief questionnaire will be completed by each subject during each treatment cycle that addresses orgasm and ejaculation quality. Safety monitoring will include adverse event reporting, laboratory assessments, and vital signs.

NCT Number	NCT07393334
Lead Sponsor	Next Life Sciences
Conditions	Male Contraception, Semen Volume, Sperm Motility
Enrollment	10 participants
Start Date	2025-12-02
Primary Completion	2026-03 (estimated)
Study Completion	2026-05 (estimated)
Updated on ClinicalTrials.gov	2026-02-06