Philadelphia, Oct. 21: Testosterone patches that boost the sex drive of older women could be launched in Britain next year following successful results from the largest trial of its kind.

In clinical tests, the hormone therapy increased desire and made sex better and more frequent among post menopausal women.

Researchers believe that the patch, known as Intrinsa, could revolutionise women?s sex lives just as Viagra helped men.

Many women suffer from reduced sexual drive and a loss of libido after the menopause. Past studies have suggested that testosterone treatment could improve their sex lives. The scientists, led by Robin Kroll, looked at 549 healthy menopausal women, aged between 40 and 70, who had complained of sexual dysfunction.

All the women in the study had been in long term stable marriages and relationships and were given the patches for 24 weeks. They were treated in Canada, America and Australia.

Half the women were given testosterone patches twice weekly, while the rest had useless, but harmless, placebo patches.

Both groups of women reported an improved sex life during the trial. Scientists say the act of taking part in the trial, talking to their partners about sex and recording their sexual activity improved their sex lives.

But the improvements among the women wearing the testosterone patches were far greater. Around 73 per cent of women wearing the patches reported an improvement in their sex lives ? compared with just 19 of the control group. Among those wearing testosterone patches, 48 per cent said their sexual desire had increased, compared with 20 per cent of the controls.

Those given the hormone treatment also reported less anxiety and distress about their sex lives. They also reported more arousal, more orgasms, more enjoyable sex, less concern, more responsiveness and improved self image.