2C-I is a psychedelic substance of the phenethylamine class. It is a member of the 2C-x family of psychedelic phenethylamines, all of which were derived from the systematic modification of the mescaline molecule.

2,5-Dimethoxy-4-iodophenethylamine, Smiles

2C-I is typically used recreationally for its psychedelic, as well as moderate stimulating and entactogenic effects. It has been explored as a potential stimulant nootropic, and has been compared to MDMA. It produces intense physical sensations, often described as an uncomfortable, tingling sensation across the body, along with physical euphoria, enhanced tactile perception, increased heart rate, dehydration, and nausea. Visual effects include color enhancement, pattern recognition, and geometric visuals similar to LSD, but less detailed. Cognitive effects include normal thought processes, empathy, and sociability enhancement in social settings, and increased music appreciation.

2C-I was first synthesized and investigated for human activity by Alexander Shulgin in 1976 and later described in his 1991 book PiHKAL. Its PiHKAL entry notes it for being “very colorful and active” but without “feelings of insight, revelation, or progress toward the true meaning of the universe.” It first briefly gained some popularity in the late 1990s and early 2000s, where it was sold in several smart shops as a replacement for 2C-B following its scheduling in 1995. It also has a history of being sold online as a research chemical before becoming scheduled.