Compound for safe male contraceptives identified

In a step towards male contraceptive pills without side effects, scientists have identified a compound that can slow the overall mobility of the sperm without affecting hormones.

Currently, condoms and surgical vasectomy are the only safe forms of birth control currently available for men. There are hormonal drugs in clinical trials that target the production of sperm, but these affect the natural hormones in men much like female contraceptives affect hormones in women.

In a study published in the journal PLOS ONE, researchers described how a compound called EP055 binds to sperm proteins to significantly slow the overall mobility of the sperm without affecting hormones, making EP055 a potential "male pill" without side effects.

"Simply put, the compound turns-off the sperm's ability to swim, significantly limiting fertilisation capabilities," said Michael O'Rand, professor at University of North Carolina in the US.

"This makes EP055 an ideal candidate for non-hormonal male contraception," said O'Rand.

During the study, thirty hours following a high-dose intravenous infusion of EP055 in male rhesus macaques, researchers at Oregon Health & Science University (OHSU) found no indication of normal sperm motility.

Further, no physical side effects were observed.

"At 18 days post-infusion, all macaques showed signs of complete recovery, suggesting that the EP055 compound is indeed reversible," said Mary Zelinski, research associate professor at OHSU.

Researchers said that more work is needed before EP055 becomes available for human use. The team has begun to test a pill form of the compound and will eventually conduct a mating trial of EP055's effectiveness against pregnancy.