2C-I

Also known as 2,5-DIMETHOXY-4-IODOPHENETHYLAMINE

Often compared to its bromine analogue because of their near-identical structures, its heavy iodine atom is central to the activity and makes it well suited to radiolabelling studies. A related ethoxy variant showed a threshold near 5 mg, with larger doses stretching the duration rather than intensifying the experience; the passage also notes a bystander's "contact high" at a group session.