The decision to make the morning-after pill more easily available has not led to the feared increase in unsafe sex, research has found.
Campaigners who opposed the introduction of the emergency pill into chemists had claimed there would be a surge in risky sexual behaviour and sexually transmitted infections.
But a study published in the British Medical Journal last week shows there was no change in contraception use levels after the emergency pill became available over the counter four years ago.
Family planning experts said the study provided a strong argument for giving it free of charge in chemists to anyone who needed it.
The study, carried out by researchers at Imperial College London, looked at survey responses from thousands of women aged from 16 to 49 who had been asked about their sex lives. They concluded there had been no significant change in use of the morning-after pill. About 8 per cent said they had taken it in each of the years that were studied.
The emergency hormonal contraceptive (EHC), which can be taken up to 72 hours after unprotected sex, was made available without prescription in Britain to women over the age of 16, at a cost of around £20, in January 2001.
One factor did change, however. The study found that, once the pill could be obtained from chemists, fewer women went to see their GP to get it while more bought it over the counter.
'These results suggest the predicted rise in unsafe sex has been overstated and supports the case for lifting the ban on over-the-counter sales in America and other countries,' said lead researcher Dr Cicely Marston.
Overall, it was found that younger women were most likely to have used it. There was a slight increase in use among 16-19-year-olds in 2001 when the change in availability was made, but this dropped in 2002. But it did not increase the proportion of women using the drug more than once during the year.
The only thing predicting whether or not women would buy emergency contraception over the counter was income. Currently, the pill costs around £25. Women with the highest incomes were more than five times as likely to report having obtained the morning-after pill in this way.
Marston and her colleagues said cost could be a barrier to some women and that lowering the price might increase the pill's use, particularly among those from lower income groups.
Researchers said their study offered little support for the argument that easier access to the pill may help prevent unwanted pregnancies. 'Women did not report more use of the method once it was made available over the counter: they seem simply to have changed where they obtained it,' Marston wrote in the BMJ .
