2C-BI-8

2C-BI-8, also known as 2,5-dimethoxy-4-(4-methoxyphenyl)phenethylamine or as 4′-methoxy-2C-Ph, is a serotonin receptor agonist of the phenethylamine and 2C families. It is the derivative of 2C-Ph (2C-BI-1) with a methoxy group at the 4 position of the added phenyl ring.

The drug binds to and/or activates the serotonin 5-HT₂ receptors. At the human serotonin 5-HT_2A receptor, its affinity (K_i) is 19 nM, activational potency (EC₅₀Tooltip half-maximal effective concentration) is 37 nM, and intrinsic activity (E_maxTooltip maximal efficacy) is 40%. These were among the most potent and efficacious in a series of evaluated 2C-Ph derivatives (2C-BI compounds) that included 2C-BI-8. However, 2C-BI-8's activational potency was about 18-fold lower than that of 2C-B and its efficacy was less than half of that of 2C-B. The drug also interacts with certain other monoamine receptors and has been assessed at the monoamine transporters. It may have the potential to produce psychedelic effects in humans.

2C-BI-8 was first described in the scientific literature by Daniel Trachsel and David E. Nichols and colleagues in 2009.