NLS-133

**NLS-133** is a proprietary, non-hormonal oral male-contraceptive candidate developed by Next Life Sciences. It is described in its registered Phase 2a study as a combination of two FDA-approved pharmacologic agents, although the constituent active ingredients have not been publicly disclosed. The product is being evaluated as an on-demand or daily oral approach intended to reduce semen volume and total sperm count for up to approximately 24 hours. Its Phase 2a crossover study in healthy men assesses effects on semen volume, sperm count, motility, morphology, ejaculation quality, and safety. ([clinicaltrials.gov](https://clinicaltrials.gov/study/NCT07393334))

Other names

silodosin + guanfacine