Norpipanone (INN, BAN; Hexalgon) is an opioid analgesic related to methadone which was developed in Germany and distributed in Hungary, Argentina, and other countries.

[2][3] It had originally not been under international control but upon observation of case reports of addiction it was reviewed and shortly thereafter became a controlled substance.

[2][3] In the United States, it is a Schedule I controlled substance (ACSCN 9636, zero annual manufacturing quota as of 2014).

The salts in use are the hydrobromide (free base conversion ratio 0.806) and hydrochloride (0.902).

This analgesic-related article is a stub.