A synthetic opioid, carfentanil is approximately 10,000 times more potent than morphine and 100 times more potent than fentanyl.
Carfentanil or carfentanyl (2-hydroxypropane-1, 2, 3-tricarboxylic acid; methyl 1-(2-phenylethyl)-4-(N-propanoylanilino) piperidine-4-carboxylateor) is a Scheduled II synthetic opioid analgesic fentanyl that is considered to be the most potent commercially used opioid and one of the most potent opiates. The drug, marketed under the trade name Wildnil, is typically only used as an anesthetic for large animals. According to the National Center for Biotechnology, carfentanil is approximately 10,000 times more potent than morphine and 100 times stronger than fentanyl. Carfentanil is used as a tranquilizing agent for elephants and other large mammals. The lethal dose range for carfentanil in humans is unknown; however, carfentanil is approximately 100 times more potent than fentanyl, which can be lethal at the 2-milligram range (photograph), depending on route of administration and other factors.