Scientists believe they are one step closer to developing an effective male contraceptive jab.
Researchers at the National Research for Family Planning in Beijing injected 1,000 healthy, fertile male patients with a testosterone-based jab over a two-year period and found only one per cent went on to father a child.
The trial was the largest effectiveness study of a testosterone-based male contraceptive ever undertaken.
At the end of the two-year period only one in 100 men had fathered a child.
No contraception is 100% effective — one to two per cent of women still become pregnant when they are on the pill.
Dr Yi-Qun Gu, one of the researchers in involved in the testing, said: “For couples who cannot or prefer not to use only female-oriented contraception, options have been limited to vasectomy, condom and withdrawal. Our study shows a male hormonal contraceptive regimen may be a potential, novel and workable alternative.”
Like the female pill, most testing for a male pill or injection has centred around using hormones to stop the production of key elements of the reproductive process.