A randomised controlled trial has found that the HIV infection rate in HIV-negative gay men who were given a daily preventative pill containing two HIV drugs was reduced by 44 per cent, compared with men given a placebo. The efficacy in subjects who, by self-report and pill count, took the drugs more than 90 per cent of the time was 73 per cent. The other big finding of the iPrEx (Pre-exposure Prophylaxis Initiative) trial was that while 93 per cent of trial subjects reported taking the pills correctly, on the basis of drug level monitoring in blood tests, only 51 per cent actually did so.