Health Studies

New Male Birth Control Injection Proves 96 Percent Effective

Researchers testing an experimental injected type of male contraception have found it to be highly effective in preventing pregnancy. This hormone shot moves science closer to finally producing a male equivalent to female contraceptives such as the birth control pill and intrauterine devices.

The shot was effective in almost 96 percent of males subjects in the test. However, there were significant side effects, so severe that the trial was brought to an early conclusion. If these cannot be overcome, the contraceptive shot for men may never be brought to market.

Clinical reproductive scientist Richard Anderson, of the University of Edinburgh in the United Kingdom, was interviewed by Hannah Devlin of The Guardian. He said:

If you’re comparing it to other reversible male methods, it’s far better than the condom and it puts it in the same ballpark as the pill. The results provide us with confidence that this can be done.

Anderson and his cohorts studied 320 healthy male subjects between 18 and 45 years of age. They received the injection, which was designed to depress sperm counts. The shot includes two hormones: progestogen, which influences sperm production through action on the pituitary gland, and testosterone, which mitigates the testosterone-reducing effects of the progestogen.

All the subjects were in long-term monogamous relationships with women partners. They were all in good health. Each subject received two injections every eight weeks, for a period of 56 weeks. Their partners discontinued any birth control as soon as the injections took effect and the men’s sperm count was reduced to less than 1 million/ml.

274 of the participants’s semen samples showed this reduced level within 24 weeks. The contraception was found effective in nearly 96 percent of the men who continued using it. There were four pregnancies during the course of the experiment, demonstrating the injection was not as reliable as the female contraceptive pill, which is 99.9 percent effective.

In a press release, researcher Mario Philip Reyes Festin, of the World Health Organization in Geneva, said:

The study found it is possible to have a hormonal contraceptive for men that reduces the risk of unplanned pregnancies in the partners of men who use it.

Obviously, the researchers were pleased with the efficacy of the injections. Unfortunately, however the side effects were extreme. Twenty percent of the subjects withdrew from the study. They had symptoms such as depression, mood disorders, injection site pain, muscle pain, increased libido and acne.

On subject committed suicide during the trial, but his death was found not to be related. The case of another subject who overdosed on acetaminophen, and another with severe depression, along with other negative effects, were judged to possibly be caused by the injections.

Although three-fourths of the men said they would be happy to continue taking the drug, the study was discontinued. Some scientists not directly involved in the trials have expressed concern about how many side effects were observed.

Other research into male contraception is ongoing, and there are several promising studies that indicate a safe, effective male contraception may be on the horizon.