Nov. 28 (Xinhuanet) -- A side-effects-free male contraceptive pill is being
developed which can be taken as a one-off dose just before a date, according to
researchers at King's College, London.
This kind of hormone-free tablet could prevent a man
from being able to impregnate a woman, but within a few hours his fertility
would return to normal.
"If the man was taking the pill over a period of
several months and decided to come off it, we would expect his fertility to
return just as quickly as if he had taken it on a one-off basis," said Dr
Christopher Smith, a researcher from King's College.
The results of trials on laboratory animals,
published in the Nature Medicine journal, had shown the contraceptive effect is
reversible, with no apparent long-term side effects. It is hoped human trials
will start shortly and the pill is on the market within the next five years.
Annual worldwide sales of the female pill are worth 41 billion U.S. dollars a
Currently, men who want to take responsibility for
contraception have limited choice, with their options extending to condoms, a
vasectomy, or simple abstinence.
Professor John Guillebaud, one of Britain's leading
experts on contraception, described the pill as "a brilliant discovery."
He said its strength lay in its ability to prevent
pregnancy without using hormones which could cause side-effects such as hot
flashes and moodiness.