Virodhamine (OAE)
A fifth endocannabinoid, virodhamine, or O-arachidonoyl-ethanolamine (OAE), was discovered in June 2002. Although it is a full agonist at CB2 and a partial agonist at CB1, it behaves as a CB1 antagonist in vivo. In rats, virodhamine was found to be present at comparable or slightly lower concentrations than anandamide in the brain, but 2- to 9-fold higher concentrations peripherally.