According to a study published in the August 17, 2012 edition of Cell, a male contraception may be possible. In the past, male contraceptive pills have been difficult because the testis has a barrier which is difficult to penetrate. In addition, male contraceptive pills containing hormones can alter testosterone levels, causing other problems in men.
An article on ScienceDaily indicates that the lack of reliable birth control for men, at least in part, contributes to the high rate of unplanned pregnancies. While female contraceptives are widely available and more reliable for females, almost one-third of couples rely on male contraceptive methods, such as condoms.
The new study used mice and has not been tested in humans. However, the results were promising. According to the researchers, a compound, targeting a testis-specific protein, lowers sperm count and causes the sperm that is produced to behave slower than normal. The mice did not show any adverse reactions in testosterone or behavior.
When the mice were taken off the compound, sperm counts returned to previous levels, indicating that the effects of the compound are completely reversible. When the mice did produce offspring after the compound was discontinued, there were no abnormalities or adverse effects on the offspring.
Because tests were completed in mice, there is a long process before this could be used in male humans, however, the researchers are optimistic, stating, “We envision that our discoveries can be completely translated to men, providing a novel and efficacious strategy for a male contraceptive.” 
 “Finally, the Promise of Male Birth Control in a Pill: Compound Makes Mice Reversible Infertile,” 2012, Aug 16, Staff Writer, ScienceDaily.com
Published On: October 07, 2012