Researchers already knew that a serine/threonine kinase 33 (STK33) gene mutation results in the male being sterile. When Baylor College of Medicine researchers found a small-molecule compound that could knock out STK33 temporarily, it produced the same result.
(STK33), a protein that is specifically required for fertility in both men and mice. As such an inhibitor called CDD-2807 has been tested and able to cross the blood-testis barrier, and travel straight for STK33 affecting sperm numbers and motility, effectively thwarting fertility even at a low drug dose.
Other key updates utilizing non-hormonal compounds can also be delineated. In late 2022, researchers at the University of Minnesota in the USA reported positive results from a study on a non-hormonal male contraceptive pill that targets vitamin A metabolism. The pill was effective in temporarily preventing sperm production in mice without any observed side effects.
In early 2023, a startup company called YourChoice Therapeutics announced they were advancing towards human clinical trials with their experimental non-hormonal male contraceptive pill called NMPA-RP-01. The pill targets retinoic acid receptor proteins in the testes.
Researchers at Purdue University and UCLA were also working on non-hormonal compounds that could temporarily render sperm non-motile or unable to fertilize an egg.
Developing a safe, effective and reversible non-hormonal contraceptive for men remains an active area of research, but an approved product may still be several years away based on the typical drug development timelines.
Ref:
https://newatlas.com/jq1-male-contraceptive/23743/?itm_source=newatlas&itm_medium=article-body 
