Fentanyl, while providing great help and hope to those suffering from chronic pain throughout the United States, has also been the cause of tragic suffering and death for hundreds of thousands of people. Synthetic opioids such as fentanyl and its chemical variants or analogues are significantly more potent and lethal than heroin.  Carfentanil, for example, is an analogue of fentanyl that is approximately 100 times more potent than fentanyl and approximately 1,000 times more potent than heroin.  Its commercial uses include serving as a tranquilizer for large animals such as elephants and rhinoceroses.  Even the tiniest amount of a fentanyl analogue – just a few grains, less than an eighth the size of a penny – can be fatal to humans.