Herkinorin is an opioid analgesic that is an analogue of the natural product salvinorin A.

It was discovered in 2005 during structure-activity relationship studies into neoclerodane diterpenes, the family of chemical compounds of which salvinorin A is a member.

[4] A study in primates showed it to act peripherally as both a μ- and κ-opioid receptor agonist, with a fast onset of action.

The study did not find any evidence of central activity in primates and questions whether herkinorin's effects are due entirely to peripheral binding.

[6] This means that herkinorin may not produce tolerance and dependence in the same way as other opioids, although some development of tolerance through other mechanisms has been observed,[7] and some other analogues related to herkinorin can recruit β-arrestins.