ROCKVILLE, MARYLAND — Government researchers in the U.S. are getting ready to test a topical contraceptive gel designed to lower sperm production. <br /> <br />The clinical trial will begin in April and run for around four years, and will be the largest study conducted to test a hormonal form of male birth control, MIT Technology Review reported. <br /> <br />Researchers at the National Institute of Child Health and Human Development are working on a hormonal gel that reduces sperm count when applied to the skin. <br />The gel contains two synthetic hormones — nestorone and testosterone. <br /> <br />The nestorone blocks the testes from making enough testosterone to produce normal levels of sperm. <br /> <br />The synthetic testosterone is needed to prevent hormonal imbalance caused by the nestorone. <br />More than 400 couples in the U.S., the U.K., Italy, Sweden, Chile and Kenya will participate in the clinical trial. <br /> <br />Couples will use the treatment for over four months while their sperm levels are checked. <br />Men in the study will take home a bottle of the gel and rub around half a teaspoon of it on their upper arms or shoulders every day. The gel takes about a minute to dry. <br />According to researchers, the gel can lower sperm count for about 72 hours.
