A Berlin-based pharmaceutical company, Schering, has obtained promising results in the development of a male contraceptive pill.
The male contraceptive, which comes almost 45 years after Schering developed the female contraceptive pill, is just skin deep - in the form of an implanted hormonal capsule and an injection given every few months.
This project is headed by a slightly-built 53-year-old woman, Professor Ursula-Friederike Habenicht, who runs the global Gynaecology and Andrology Research sector for Schering.
"This is just an initial step, just getting a foot in the door," says Habenicht, who has long been considering possible approaches to male contraception.
Habenicht is in charge of a large group of scientists who are pursuing these ideas in teams scattered through various laboratories.
The main problem facing the researchers is the fact that a woman releases just one egg per month that might be fertilised, whereas a man produces between 70 and 100 million sperm per day - and all of these without exception have to be reined in.
"The combination of the gestagene (hormonal capsule) implant and the testosterone injection causes the brain to stop the sperm production in the testicles," the professor says.
This occurs because the procedure artificially increases the level of body's testosterone, leading the brain to believe that sufficient sperm are already present. It therefore ceases to send out signals ordering further production.
Since the complete sperm production cycle requires 70 days on the average, it takes quite a while for the very last little critter to disappear. Only after three to six months is the sperm count reduced to zero.
"This long preliminary stage cannot be altered biologically," the professor explains.
Furthermore, there is still no substitute for the bothersome injection. "If you swallow testosterone in pill form, it is broken up in the liver and rendered useless," Habenicht adds.
Nevertheless, she is confident that men will accept this form of contraception. "For many, according to surveys, this is an alternative to cutting the vas deferens", the sperm duct that runs from the testicle to urethra.
She notes that around 60 million men around the globe have been sterilised - a number similar to that of women taking the pill. But unlike sterilisation, the effect of the injection can be reversed after a certain period.
In spite of all this, the approximately 80 scientists spread around the world are also looking into other approaches - with special attention being paid to the epididymis, the part of the testicles where the sperm ripen.
"We have already identified a chemical candidate which can prevent this ripening process," says Habenicht.