25B-NB, also known as N-benzyl-4-bromo-2,5-dimethoxyphenethylamine (N-benzyl-2C-B or NB-2C-B), is a recreational designer drug from the 25-NB subgroup of the substituted phenethylamine family, with psychedelic effects. It has a binding affinity (K<sub>i</sub>) of 16 nM at the serotonin receptor 5-HT<sub>2A</sub> and 90 nM at 5-HT<sub>2C</sub> and reportedly has a potency in between that of 2C-B and 25B-NBOMe (NBOMe-2C-B). 25B-NB was first synthesized and described by Richard Glennon and colleagues in 1994. It was the first drug of the 25-NB family to be developed. Subsequently, modification of 25B-NB led to the development of the more well-known 25-NB family drugs such as 25I-NBOMe. 25B-NB is a controlled substance in Canada under phenethylamine blanket-ban language.