Researcher in a greenhouse of opium poppies, placing a paper bag over a genetically-modified poppy to prevent cross-pollination. This poppy (Papaver somniferum) is the source of opium, a narcotic resin that contains the alkaloids morphine and codeine. These are used by the pharmaceutical industry as painkillers (analgesics). Geneticists have used genetic- modification to develop new varieties of the poppy that produce more of its active ingredient morphine and an increased crop yield. Opium can be refined to yield pure heroin, an illegal drug that induces feelings of warmth and euphoria. Frequent use leads to an increase in tolerance and addiction. Photographed in France.