Skip to content
Bored Studies
RecruitingAccepts healthy volunteersPhase 2

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

Next Life Sciences · NCT07393334

View Study & Apply (opens in a new tab)

Opens the official ClinicalTrials.gov record, with the study team’s contacts. Bored Studies doesn’t enroll anyone.

Key facts

Compensation
Not posted. Ask the study team before screening.
Who can join
Ages 18–55 · Men only
Healthy volunteers
Accepted
Study type
Interventional · Phase 2
Target enrollment
10
US sites recruiting
1
Study start
December 2, 2025
Record last updated
February 6, 2026

Status re-checked against ClinicalTrials.gov within the last 12 hours.

What the study is about

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.

Being studied: NLS-133; Placebo; Active Comparator #1

Conditions: Male Contraception; Semen Volume; Sperm Motility

Eligibility criteria

Copied from the official record. The study team makes the final decision at screening.

Show full criteria

Inclusion Criteria

  • Male, age 18-55.
  • Normal physical examination and testicular volume >15 cc
  • No significant medical history that would impact the safety of the study.
  • No current use of drugs that comprise NLS-133
  • Normal values on baseline hematology, blood chemistry and liver function tests and serum testosterone.
  • Normal baseline sperm parameters (semen volume >1.4 cc, sperm concentration >15 million/ml, motility >40% and morphology >4%).
  • Willing and able to comply with all study requirements and procedures.

Exclusion Criteria

  • History or evidence of erectile dysfunction.
  • Inability to produce semen samples in clinic setting.
  • Significant chronic or acute medical illness.
  • Previous or current ethanol or illicit drug abuse.
  • Evidence of significant underlying disease (based on results of the physical exam and the routine labs).
  • Known infertility or hypogonadism.
  • Planned or anticipated use of any prohibited medications during participation in the study. These include use of sex hormones for treatment, testosterone, anabolic steroids, retinoic acid (e.g., Accutane®), vitamin A, other drugs known to inhibit spermatogenesis, opioids, cocaine, methamphetamine, and/or the consumption of >4 alcoholic beverages daily.
  • Presence of moderate-to-severe pulmonary or cardiovascular disease
  • Known active hepatitis B, hepatitis C, human immunodeficiency virus (HIV), or COVID-19 infection.
  • History of malignancy within 5 years before the Screening Visit, except fully treated and resolved non-metastatic squamous or basal cell carcinoma of the skin.
  • Known active chronic or acute infection requiring treatment with systemic antibiotics, antivirals, antifungals, antiparasitics or antiprotozoals during the Screening period.
  • Any other acute or chronic medical or psychiatric condition or laboratory abnormality that could increase the risk associated with study participation in the judgment of the investigator would make the participant inappropriate for entry into the study.
  • Participation in another investigational clinical trial within the last 30 days.
  • Participants who live in detention on court order or on regulatory action.
  • Related to sponsor or staff involved in the conduct of the study.

Recruiting US locations

  • Population Center for Research in Human Reproduction and Departments of Medicine, University of Washington

    Seattle, WA 98195

    Site contact: John K Amory, MD, MPH, MSc · (206) 616-1727 · jamory@uw.edu

Study contacts (from the official record)

  • John K Amory, MD, MPH, MSc · (206) 616-1727 · jamory@uw.edu
All women’s health studies in Washington →
Effects of NLS-133, a Potential Non-Hormonal "On-Demand" Male… (NCT07393334) | Bored Studies