Women may soon be able to use a stick-on patch to boost their sex drive. The patch is worn on the stomach for two weeks at a time and delivers the hormone testosterone, which has been linked to female sexual desire. A trial involving 562 women who had had hysterectomies found the patch led to a 74% increase in satisfying sex. Manufacturers Procter & Gamble are hoping to launch the patch in the US shortly and in the UK within the next two years. The patch will be aimed at women with hypoactive sexual desire disorder (HSDD) - a lack of sexual desire that causes them distress.