Researchers have created a drug that specifically targets a protein in the testes and stops sperm production in mice, and is reversible – so has potential as a male contraceptive pill. However… one of the effects is shrinking testes, and though it’s reversible, how would people cope with that? And the age old question too – would women trust their partners to take the pill? These aren’t questions that need answering quite yet as it has only been tested in animals so far. As Professor Moira O’Bryan, the head of male infertility at Monash University in Australia, said to BBC News: “Although there is undoubtedly an urgent need for additional contraceptive options, the path between this paper and a new product is likely to be long.”

Read the original research in the journal Cell, and there’s more information here and here.