25B-NBOH (2C-B-NBOH, NBOH-2C-B) is a derivative of the phenethylamine derived hallucinogen 2C-B which has been sold as a designer drug. It acts as a potent serotonin receptor agonist with similar affinity to the better-known compound 25B-NBOMe at 5-HT2A and 5-HT2C receptors with pKis values of 8.3 and 9.4, respectively.