Carfentanil is a very strong synthetic opioid. Mostly, it comes as a crystalline powder or white granular. When used as an analytical reference chemical, it comes as a pale yellow solid which can dissolve in chloroform, ethyl acetate, and dichloromethane.

According to reports, Carfentanil was first synthesized in 1974. The makers of the drug first designed it for use in tranquilizing huge animals. Because it is a very strong synthetic opioid, it is used in sedating huge animals such as elephants. Carfentanil belongs in the same class as substances like heroin, fentanyl and prescription pills like oxycodone. Note that Carfentanil is not like other opiates. It is extremely strong and might not be recommended for human use.