“Unlike the poppies needed for heroin, which can be spoiled by weather or a bad harvest, fentanyl’s ingredients are easily supplied; it’s a synthetic combination of chemicals, often produced in China and packaged in Mexico, according to the U.S. Drug Enforcement Administration. And because fentanyl can be 50 times more powerful than heroin, smaller amounts translate to bigger profits.” The first wave was prescription painkillers, the second wave was heroin. NPR: The U.S. Opioid Epidemic’s Third Wave Begins.