25B-NBOMe

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 5HT_2A 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.

The carbon-11 labeled version of this compound ([¹¹C]Cimbi-36) was synthesized and validated as a radioactive tracer for positron emission tomography (PET) in Copenhagen. As a 5-HT_2A receptor agonist PET radioligand, [¹¹C]Cimbi-36 was hypothesized to provide a more functional marker of these receptors. Also, [¹¹C]Cimbi-36 is investigated as a potential marker of serotonin release and thus could serve as an indicator of serotonin levels in vivo. [¹¹C]Cimbi-36 is now undergoing clinical trials as a PET-ligand in humans.