Reversible non-hormonal male contraceptive that targets the STK33 protein

Reversible male contraception by inhibition of serine/threonine kinase 33

NIH-funded research Baylor College of Medicine · NIH-11321660

Developing a non-hormonal medicine that temporarily blocks a sperm-related protein (STK33) to provide reversible contraception for adult men.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionBaylor College of Medicine NIH-funded
Lab location1 site (Houston, United States)
Project IDNIH-11321660 on NIH RePORTER

What this research studies

Researchers are creating and testing drug candidates that selectively block the STK33 enzyme, which is enriched in the testes and needed for normal sperm shape and movement. They used DNA-encoded chemistry to screen billions of compounds and are optimizing molecules for potency, metabolic stability, and to remain outside the brain (peripherally restricted). Findings from mice lacking STK33 and a human family with an STK33 mutation that causes infertility guide the work, but the current work is preclinical lab and animal testing rather than treatments available to patients. If the best molecules are found, they would move into safety studies and future clinical trials in men.

Who could benefit from this research

Good fit: Adult men (21+) who want reversible contraception and would consider enrolling in future clinical trials are the most likely candidates.

Not a fit: Women, minors, people seeking permanent sterilization, and men with infertility unrelated to STK33 are unlikely to benefit from this research in the near term.

Why it matters

Potential benefit: Could provide the first reversible, non-hormonal male contraceptive option that avoids altering systemic hormones.

How similar studies have performed: Genetic studies in mice and a human family show that loss of STK33 causes male infertility, but using drugs to reversibly block STK33 in humans is a novel and unproven approach.

Where this research is happening

Houston, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.