A birth control shot for men shows some promise, but researchers are still struggling to improve its effectiveness and deal with severe side effects caused by the injections.
Only four pregnancies occurred among 266 men receiving the treatment, which is an effectiveness rate comparable to other contraceptive methods, according to results from a new international clinical trial.
But the men also experienced mood swings and depression so frequently that a safety review committee halted the study early, the researchers reported.
No further development is planned for this particular birth control shot for men, but the clinical trial showed that such an injection can suppress sperm counts and prevent pregnancy, said researcher Dr. Mario Festin. He is a medical officer with department of reproductive health and research at the World Health Organization.
“A male hormonal contraceptive is possible,” Festin said. “We have to continue searching for or investigating the right drugs, and their combinations, with the highest efficacy and safety, and acceptability, with the least side effects.”
The concept of a male birth control shot based around the hormone testosterone has been around for decades, said Dr. Edmund Sabanegh, director of the Center for Male Fertility at the Cleveland Clinic.
Such an injection can trick the testicles into reducing production of the highly concentrated testosterone they need to create sperm, Sabanegh said.