06 May 2009
Popular male birth control methods may become obsolete with the development of a contraceptive jab sans side effects
Chinese researchers are on track to create an effective male contraceptive jab with none of the usual side effects, a development that would revolutionize family planning. The testosterone injection works by temporarily halting sperm production by reducing levels of two regulatory brain chemicals.
Previous attempts to develop an effective and convenient male contraceptive have encountered problems over reliability and side–effects, such as mood swings and a lowered sex drive.
The study, which will appear in the June issue of the Journal of Clinical Endocrinology and Metabolism, was backed by the World Health Organisation.
Researchers were able to achieve a 99 per cent success rate by injecting men with testosterone in a trial that they claim is the largest so far conducted anywhere in the world.
The latest research, conducted 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 1 per cent went on to father a child, The Independent newspaper reported yesterday.
The study is the largest multi–center, male hormonal contraceptive efficacy clinical trial of an androgen preparation in the world.
Participants included 1,045 healthy fertile Chinese men aged 20–45 years. Each participant had fathered at least one child within the two years before the study and had a normal medical history. Their female partners were between 18 and 38 years of age and had normal reproductive function. Researchers monthly injected males with 500 mg of a formulation of testosterone undecanoate (TU) in tea seed oil for thirty months.
They found that a cumulative contraceptive failure (pregnancy) rate of 1.1 per 100 men in the 24–month efficacy phase. No serious adverse events were reported and reproductive function returned to the normal fertile reference range in all but two participants.
“For couples who cannot or prefer not to use only female–oriented contraception, options have been limited to vasectomy, condom and withdrawal,” said Dr Yi–Qun Gu, the lead researcher.
“Our study shows a male hormonal contraceptive regime may be a potential, novel and workable alternative,” he was quoted as saying by the British daily.