25N-NBPh (NBPh-2C-N) is a phenethylamine derivative from the 25-NB class, which acts as a potent agonist at the 5-HT<sub>2A</sub> receptor with weaker activity at 5-HT<sub>2B</sub> and 5-HT<sub>2C</sub>. 25N-NBPh is a biased agonist, producing robust activation of 5-HT<sub>2A</sub> coupled signalling pathways mediated by beta arrestin 2, but with only slight activation of pathways mediated via G<sub>q</sub>. In animal studies it produces a modest head-twitch response when administered by itself, but blocks the effects of the fully active psychedelic DOI.