NEW ORLEANS- (WGNO) -- What at first appeared to be a miracle to control pain for suffering patients, has become a death knell for millions of illegal drug users-- many of whom have no idea what they're taking. Fentanyl is a synthetic opioid, meaning that it has none of the natural opium made from harvested poppies. Examples of natural opioids are morphine and codeine. Saving a Generation: The Fentanyl Crisis Instead, fentanyl is a combination of chemicals, made in a lab, created in the United States in the 1960's as a cheap but powerful pain-killer. According to the Centers for Disease Control and Prevention (CDC), fentanyl is often "prescribed by doctors to treat severe pain, especially after surgery and for advanced-stage cancer." The CDC says fentanyl is "fifty times more potent than heroin, and 100 times more potent than morphine." Medical fentanyl is most often sold in pharmacies as a transdermal patch. But black market labs, often in China, make liquid fentanyl, which can be used as illegal eye drops or nasal spray, and powdered fentanyl, which can be pressed into pills. And because fentanyl is cheaper to produce than natural opioids, the CDC says drug dealers often sell drugs like heroin, laced with fentanyl, to increase their profits-- without telling drug buyers. Pharmaceutical fentanyl vs. illegal fentanyl: What’s the difference? According to the Drug Enforcement Administration, fentanyl has become the "leading cause of death for Americans between the ages of 18 to 45." In Louisiana, Tangipahoa Parish Sheriff Gerald Sticker says Mexican drug cartels bring fentanyl into his parish via two major interstates, I-12 and I-55. Sticker says he can't close that "pipeline." But he says he intends to "harass" suspected drug dealers "until they move on and set up shop somewhere else." Stay up to date with the latest news, weather and sports by downloading the WGNO app on the Apple or Google Play stores and by subscribing to the WGNO newsletter. Latest Posts October Prime Day Dyson deals Levi's are deeply discounted for October Prime Day, with jeans starting at $13 The best Prime Day Lego deals on sets that rarely go on sale I’m a 50-year-old deals editor and buying these 10 Prime Day beauty deals NOW Epic Prime Day beauty deals you should add to your cart now, according to a beauty editor