A study recently published in Nature Communications (Balbach et al., 2023) has shown a proof-of-concept for an innovative way to provide on-demand contraception in males. The birth control pill is expected to be taken shortly before sex and would involve blocking a key protein involved in the motility and maturation of sperms, soluble adenylyl cyclase (sAC).
The study has been conducted in mice where a single dose of sAC inhibitor renders the male mice temporarily infertile while they continue to exhibit normal sexual behavior. Full fertility returns the very next day.
Multiple studies surrounding contraceptive pills in males have been undertaken in recent years with limited success. While female contraceptives target a single egg, millions of sperms need to targeted in male contraceptives. In addition, the tolerance for side-effects in male contraceptives is very limited compared to women. In women, side-effects are weighed against the risk of pregnancy and society often puts the burden of contraception on them. Male contraceptives also target hormones which can lower testosterone levels, thus affecting libido.
To get around the testosterone problem, researchers have added testosterone-like compounds to the contraceptives. Trials are underway to know if this approach works. In another approach scientists have developed a gel-like substance which blocks the tubes that carry the sperm from the testicles. This approach provides contraception for about two years.
The method employed by Dr Melanie Balbach (Weill Cornell Medicine in New York) seems to be the most innovative so far as the contraception is highly targeted and temporary, both properties of an ideal contraceptive pill. In addition, it does not interfere with the function of any hormone and thus libido is undisturbed.
Experts warn that while this approach may prevent pregnancy, it does not provide any protection from sexually transmitted diseases. In addition, the studies so far have been in mice only, replication in human subjects is a much bigger challenge that remains to be addressed.
- Male contraceptive pill prototype stops sperm swimming. BBC News [Internet]. 2023 Feb 14 [cited 2023 Feb 24]; Available from: https://www.bbc.com/news/health-64635446
- Davis N, Correspondent NDS. Male contraceptive taken shortly before sex shows promise, say scientists. The Guardian [Internet]. 2023 Feb 17 [cited 2023 Feb 24]; Available from: https://www.theguardian.com/society/2023/feb/17/male-contraceptive-taken-shortly-before-sex-shows-promise-say-scientists
- Balbach M, Rossetti T, Ferreira J, Ghanem L, Ritagliati C, Myers RW, et al. On-demand male contraception via acute inhibition of soluble adenylyl cyclase. Nat Commun. 2023 Feb 14;14(1):637.