Male contraceptive trial moves to Manchester

Want to test a male contraceptive?

Researchers at The University of Manchester, working in collaboration with nine other centres across the world, are asking men in stable relationships to take part in the trial of the hormonal contraceptive.

The research, which follows a similar trial in China published earlier this month involving testosterone injections, will involve male volunteers aged 18 to 45 being given injections of testosterone along with a second hormone that has been shown to reversibly suppress sperm production.

The manchester team say: 'the combination of two hormones means the trial will require half the frequency of injections as the Chinese study. The two hormones — Norethisterone enantate and Testosterone undecanoate — have already undergone trials to test their safety and were shown to have only mild side-effects in a small number of individuals.'

High drop-out rate

In the Chinese research, the treatments was 99% effective and, indeed, no serious side-effects were reported but some have questioned the research. For example, 1045 men started the trial but only 733 completed it - a pretty high drop-out rate.

The BMJ also warns about the time it took for sperm counts to return to normal: 'For most men it took around 200 days for their sperm count to get back to normal, but 17 men still hadn't recovered their fertility after a year.'

The Manchester trial will initially involve up to four courses of injections over six months, during which time the men's sperm count will be measured to ensure it is below fertility levels.

The couples — 60 in Manchester and a further 340 internationally — will then be asked to rely solely on the hormonal method for 12 months while the male partner continues to receive the injections every eight weeks.

At the end of the trial period, the men's sperm count will continue to be monitored to assess how quickly fertility levels return to normal.

What do you think? Fancy taking part? Would you take a male contraceptive jab?

• Further information on the trial