25B-NBOMe (NBOMe-2C-B, Cimbi-36, Nova, BOM 2-CB) is a derivative of the phenethylamine psychedelic 2C-B, discovered in 2004 by Ralf Heim at the Free University of Berlin. It acts as a potent partial agonist for the 5HT2A receptor. Anecdotal reports from users suggest 25B-NBOMe to be an active hallucinogen at a dose of as little as 250–500 µg, making it a similar potency to other phenethylamine derived hallucinogens such as bromo-dragonfly. Duration of effects lasts about 12–16 hours.