Researchers at Weill Cornell Medicine are developing an experimental male contraceptive pill that temporarily blocks sperm motility. The drug could be taken approximately 30 minutes before sexual intercourse, and its effects would last for 6\u20138 hours. The US National Institute of Child Health and Human Development (NICHD) has awarded the scientists an $8.2 million grant to support further research on the project.<\/p>\n
Pharmacologists Jochen Buck and Lonny Levin are working on the drug. The four-year grant will allow them to investigate its toxicity and safety, which are essential before clinical trials in humans can begin. At this stage, the drug remains experimental, and its safety and effectiveness in humans have not been established.<\/p>\n
How does the drug work?<\/p>\n
The new contraceptive pill works by targeting an enzyme known as soluble adenylyl cyclase (sAC), which is essential for sperm motility. The researchers discovered that temporarily inhibiting this enzyme can stop sperm from moving without blocking sperm production.<\/p>\n
After the pill is taken, its active ingredient reaches sperm cells and inhibits the sAC enzyme. As a result, sperm can no longer move properly and have difficulty reaching the egg. As the concentration of the drug in the body decreases over time, the enzyme’s activity is restored, and sperm motility returns to normal.<\/p>\n
A preclinical study published in Nature Communications in 2023 showed that blocking the sAC enzyme rendered sperm immotile and prevented fertilization and pregnancy in experimental models.<\/p>\n
How does it differ from other contraceptive methods?<\/p>\n
Many other experimental approaches to male contraception affect sperm production. This process takes approximately two and a half months, meaning that it may take weeks or months for these methods to become effective and for fertility to recover after their use is discontinued.<\/p>\n
The new drug acts on sperm that have already been produced, allowing it to work more quickly and temporarily. The pill could be taken as needed rather than daily. The researchers aim to offer men an additional contraceptive option and help promote shared responsibility for preventing unintended pregnancies.<\/p>\n
When will the pill become available?<\/p>\n
The researchers hope to begin the first clinical trial in humans in approximately two years. Before that, the drug must undergo additional safety testing in animals. In the first phase, scientists will assess potential side effects and determine how effectively and temporarily the drug blocks sperm motility.<\/p>\n
The researchers have not observed side effects in animal experiments, but this does not guarantee safety in humans. Further studies are needed to determine whether inhibiting the sAC enzyme also affects other tissues and whether sperm motility remains suppressed after sperm enter the female reproductive tract.<\/p>\n
Additional clinical trials in humans, including studies involving couples, will eventually be needed to confirm the drug’s effectiveness. Therefore, despite promising preclinical results, several stages of research remain before the drug could become widely available.<\/p>\n