Why are we still waiting for a male contraceptive pill?

Despite research into a male contraceptive pill starting around the same time as its female counterpart, no product has ever made it to market. But that could soon change, with a new non-hormonal male pill entering human trials in the UK late last year. Ian Sample speaks to bioethicist Prof Lisa Campo-Engelstein of the University of Texas and Prof Chris Barratt from the University of Dundee about why male contraceptives have been so difficult to develop, and what kind of options are in the pipeline. Help support our independent journalism at theguardian.com/sciencepod