A new male birth control may be coming soon.
The largest clinical trial of hormonal male contraception will begin in the first half of 2018 with the goal of enrolling more than 400 couples in six countries around the world. Once a day, men apply synthetic hormone-containing gels to the upper arm and shoulders, and researchers will track the effects of gels on preventing mate pregnancy.
The trial, sponsored by the National Institutes of Health and the Nonprofit Population Council, will include couples in the United States, Britain, Italy, Sweden, Chile and Kenya. The experimental gel contains a synthetic progestin called nestorone – prevents the testicles from producing enough testosterone to produce sperm – and synthesizes testosterone, which counteracts the subsequent hormonal imbalance.
A different combination of progestin and testosterone was previously tested in a smaller clinical trial released last year and men were given hormone injections every two months. The researchers found that these shots have a 96% effect in suppressing sperm count, but studies were earlier than expected due to complaints from people in the study about mood swings, muscle pain and other side effects.
Dr. Min Lee, a researcher on the forthcoming trial, a researcher at the National Institute of Child Health and Human Development, said that contraceptive gels contain much less synthetic testosterone than injections, and many of these problems are expected to be avoided. “If we stop testosterone, then men obviously will experience side effects other than sperm count.” “But we just added it back so they had a normal physiological response instead of the mass used in other formulas,” he said.
Lee said topical use of the nestorone / testosterone combination also showed promise in a six-month 2012 clinical trial, but the study involved two different gels that had to be applied to different parts of the body. In the past few years, he said, researchers at the National Institutes of Health and Population Commission have re-assembled the gels into a single product.
Women in the trial also used a female contraceptive during the first four months of the contraceptive gel used by the male partner. However, once men have less sperm than the threshold needed to prevent pregnancy (less than one million per milliliter), the couple will only use gels as a one-year contraceptive.
Gels have been shown to inhibit sperm levels for about 72 hours. If people forget the dose, it means “a little bit of forgiveness,” and Regine Sitruk-Ware, an eminent scientist of the Population Commission, recently told the MIT Technical Review.
Even if the drug is successful, Lee said it may be open to the public at least five years after the Food and Drug Administration approves it. As soon as the upcoming phase IIb trial is completed, a larger phase III trial will be required.
But he is hopeful about the future of male contraception and said the new study is an important step toward reality. Research by his team also shows that there is a demand for the product.
Lee said: “If you asked me two years ago if this is a useful contraceptives, I would hesitate, said:” Who would like to gel this body? “But in our interview, men told us they are very happy to do that. Both the investigators and the people involved have a lot of enthusiasm. “