2C-I

2C-I is a widely encountered 2C-series psychedelic phenethylamine bearing an iodine substituent at the 4-position. It acts principally as a 5-HT2A receptor agonist and reliably induces the 5-HT2A-mediated head-twitch response in mice, a behavioral proxy for hallucinogenic activity that is fully blocked by the selective antagonist M100907. Its scaffold is of particular pharmacological interest because N-benzylation to form 25I-NBOMe increases 5-HT2A affinity and in vivo potency by more than an order of magnitude, yielding a far more dangerous derivative that is sometimes mis-sold as 2C-I. 2C-I itself is characterized by bright, colorful visuals with a moderate stimulating quality, is metabolized largely via CYP2D6, and produces only limited monoamine oxidase inhibition. It is detectable in the urine of users among panels of 2C designer drugs.