A new and improved hormone free contraceptive for men may be in the offing. Researchers have isolated a small molecule that may offer the first effective and hormone-free contraception for males, ever since the development of condoms. The study shows that this compound makes male mice reversibly infertile without loss of libido. When they stop taking this new form of birth control, their sperm rebound and they are again able to sire perfectly healthy offspring.
“This compound produces a rapid and reversible decrease in sperm count and motility with profound effects on fertility,” said James Bradner of the Dana-Farber Cancer Institute, Boston, who co-authored the study with Martin Matzuk from Baylor College of Medicine. A male birth control pill has not been easy to come by in large part because of the challenge of getting any drug across the blood-testis barrier, where it can reach the sperm-generating cells, according to a Dana-Faber statement.
Known as JQ1, the compound developed in the Bradner lab works by targeting a testis-specific protein called BRDT that is vital for fertility. When mice are given the BRDT-inhibiting molecule, they begin producing fewer sperm and those sperm they do produce do not swim as well. “This is a good reason to get excited about low sperm counts,” said Matzuk from Baylor. JQ1 indeed works as effective contraception. The small molecule also comes without any apparent adverse effects on the males’ future offspring. “There has not been a new reversible contraceptive for men since the development of the condom,” notes William Bremner from the University of Washington, Seattle in a commentary in which he refers to Matzuk and Bradner’s contraceptive method as “a breakthrough new approach”.