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There are currently about 15 methods of contraception publicly available, but only two are available to males: condoms and vasectomy.
For decades, men have had to rely on these two birth control methods, whereas women have had access to the oral contraceptive pill since 1960, when it was approved in the United States. Recent scientific experiments have raised hopes that more male contraceptives, such as a contraceptive injection, a male birth control pill, and a body gel, will soon be available for consumer use.
Indian scientists have recently announced that clinical trials have been completed on the world’s first contraceptive injection for men, named the Reversible Inhibition of Sperm Under Guidance (RISUG). Dr Sujoy K. Guha, a biomedical engineer at the Indian Institute of Technology in Kharagpur and the RISUG research team leader published the results of the clinical trials, reporting a 97.3 per cent success rate in preventing pregnancy with no known side-effects in a six-month period.
The contraceptive contains Styrene Maleic Anhydride, a polymer which inhibits sperm production and works via a gel injection to a sperm-containing tube near the testicles. Dr Guha supports that RISUG is a long-active contraceptive which will be effective for 13 years and is non-hormonal.
However, some researchers have questioned whether RISUG can work as a reversible method of contraception. Michael Skinner, a reproductive biologist at Washington State University, has argued that it is not clear that RISUG is very different from sterilisation as its reversibility has not yet been demonstrated. Indeed, the effectiveness of the second part of the treatment, which dissolves the gel injected and enables the male to have children, has worked in animal studies but is yet to be tested on humans.
Research on other contraceptive methods, such as a male birth control pill, is also underway. Researchers at the Los Angeles Biomed Research Institute have developed 11-beta-MNTDC, an experimental male oral contraceptive, which is a modified testosterone that combines the actions of androgen, a male hormone, and progesterone. When taking the pill during the trials, participants’ testosterone levels fell and sperm production dropped greatly, returning to normal levels after the trial.
“11-beta-MNTDC mimics testosterone through the rest of the body but is not concentrated enough in the testes to support sperm production”, says Stephanie Page, M.D., Ph.D., the study’s co-senior investigator. This is done to minimise side-effects on the body due to low testosterone.
Although there were no severe side-effects reported, about ten per cent of men in the studies reported fatigue, acne, or headache, and decreased sex drive. This shows that there is still much to learn on this new product and one can safely say that there is no way to know how a new substance affects the human body when used long-term until the subjects are observed for years or decades, especially when they consume products that induce hormonal changes. Despite these worries, the study’s other co-senior investigator, Christina Wang. has said that 11-beta-MNTDC is a “safe, reversible hormonal male contraception [that] should be available in about 10 years.”
Another promising contraceptive that is currently being developed and is being tested in the UK is a body gel named NES/T. NES/T is hormone-based and contains progestogen which acts in the pituitary gland and switches off sperm production, without affecting libido. Trial participants are asked to rub the gel on their shoulders and upper arms daily so that it is absorbed by their bloodstream and will be monitored for months until their sperm count decreases significantly. Professor Richard Anderson, who is leading the study at the University of Edinburgh, says that NES/T is expected to be more effective than condoms and match the female pill’s effectiveness of 97 to 99 per cent.
However, Professor Anderson also raised concerns about the fact that the pharmaceutical industry currently underfunds male contraception studies and that lack of investment is a factor which delays research and trials on male contraception. “I think that industry has not been convinced about the potential market,” he said.
This is despite the fact that, as cited in a multinational survey of 9,000 men published in Human Reproduction, 55 per cent of men in stable relationships would be willing to try new and reversible contraceptive methods.
It’s certainly the case that the times when women were seen as being solely responsible for preventing pregnancy are now past. The burden for preventing pregnancy and family planning also falls to men and there is currently the need for reversible and highly effective male birth control.