Carraguard™ (PC-515), the Population Council's lead candidate microbicide, was tested in a randomized, controlled trial in Chiang Rai, northern Thailand. Safety of daily product use determined by symptoms of irritation, effect on vaginal flora, vaginal epithelial disruption as determined by naked eye inspection (Day 7 and Day 14 of each arm) and colposcopic inspection on (Day 7), and other adverse effects, which may include UTI or other unforeseen problems (Day 7 and Day 14).