...
By Hannah Millington
Health Reporter
0
Share
Newsweek is a Trust Project member
See more of our trusted coverage when you search.Prefer Newsweek on Googleto see more of our trusted coverage when you search.
A molecular switch that “supercharges” sperm could inspire new safe methods of contraception—including a non-hormonal male birth control pill—and improved infertility treatments.
This is the discovery of scientists from Michigan State University, Memorial Sloan Kettering Cancer Center and the Van Andel Institute, who have uncovered a rapid mechanism that helps sperm to successfully reach and fertilize an egg.
“Before sperm are ejaculated they sit around and wait in a sleep-like state. Once they are ejaculated they have to quickly start moving, which takes way more energy. It’s like if we would go from sleeping to running an ultramarathon,” study author and Michigan State molecular biologist professor Melanie Balbach told Newsweek.
Read More on Health
“This study is about understanding the fundamental mechanisms of how sperm generate more energy and which proteins are regulating this change, which can be later explored for contraception.
"If sperm are not able to generate that much more energy they are not able to fertilize.”
...
In 2023, while at Weill Cornell Medicine, Balbach helped drive the discovery that blocking another crucial sperm enzyme made mice temporarily infertile, initially raising the potential for a non-hormonal male birth control.
While it was long known that the transition from waiting to swimming calls for a large amount of energy—and a corresponding increase in metabolism—it was not known how sperm adjust to these increased demands, Balbach explained.
To investigate, the Balbach and her colleagues developed a special technique to follow the metabolism of glucose between non-activated and activated sperm.
“It’s like painting a car roof pink and following it through traffic. Through this method we now have strong hints which proteins are important to increasingly metabolize glucose,” said Balbach.
“These proteins can now be explored as contraceptive targets or can explain infertility cases where the underlying reason was unknown. This is just the first step of a decade-long process.
"We now have to acquire additional funding and identify small molecular inhibitors that block these proteins. Based on user preference, the ultimate goal would be an on-demand, reversible contraceptive administered as a pill."
The team’s discoveries also include a particular enzyme called aldolase that helps sperm convert glucose into energy and that sperm even utilize molecular fuel that they already have on board when they begin their trek.
Meanwhile, they’ve revealed how some enzymes regulate the flow of glucose like traffic controllers.
Balbach sees the ongoing analysis of sperm metabolism as a promising direction for improving both assisted fertility techniques and the diagnosis of infertility in patients.
“This approach might be another way to achieve on-demand, non-hormonal contraception. That approach is strongly desired by the target group but no similar product has made it to the market,” she said.
“The approach would potentially similarly be appropriate for non-hormonal female contraception, blocking the sperm from swimming up to the oocyte once they enter the female genital tract.”
The development of male contraceptives has traditionally focused on blocking sperm at their creation. Drawbacks include not being on demand (like not working immediately and not returning fertility immediately when stopped) and typically being hormone-based with side effects, according to the team.
The researchers’ latest findings mark a step in paving the way for an inhibitor-based, non-hormonal method of contraception that would allow for on-demand male infertility with the goal of having little side effects.
“Currently, there are insufficient contraceptive options for both males and females. While clinical trials for a hormonal male contraceptive are successful, alternative, non-hormonal and rapidly reversible methods are needed," said Balbach. Meanwhile, for women, contraceptive methods that do not cause significant side effects are lacking.
Together, Balbach said, non-hormonal contraceptives for men and women would fill an unmet need that gives both sexes more agency in fertility planning.
While more research is needed, the professor added: ”Proteins regulating metabolism are highly conserved between mammalian species. From first experiments in humans we get similar results, validating that our findings from rodents can be applied to humans.”
Do you have a tip on a health story that Newsweek should be covering? Do you have a question about birth control? Let us know via health@newsweek.com.
Reference
Balbach, M., Rossetti, T., Ferreira, J., Ghanem, L., Ritagliati, C., Myers, R. W., Huggins, D. J., Steegborn, C., Miranda, I. C., Meinke, P. T., Buck, J., & Levin, L. R. (2023). On-demand male contraception via acute inhibition of soluble adenylyl cyclase. Nature Communications, 14(1), 637. https://doi.org/10.1038/s41467-023-36119-6
Violante, S., Kyaw, A., Kouatli, L., Paladugu, K., Apostolakis, L., Jenks, M., Johnson, A., Sheldon, R. D., Whitten, D., Schilmiller, A. L., Visconti, P. E., Cross, J. R., Levin, L. R., Buck, J., & Balbach, M. (2025). Sperm meet the elevated energy demands to attain fertilization competence by increasing flux through aldolase. Proceedings of the National Academy of Sciences, 122(39). https://doi.org/10.1073/pnas.2506417122
View 0 Comments
Submit Correction
View Editorial & AI Guidelines