2-Iodo-LSD


2-Iodo-LSD is a putatively non-hallucinogenic serotonin receptor modulator of the lysergamide family related to 2-bromo-LSD and lysergic acid diethylamide. It is the 2-iodo derivative of LSD.

Use and effects

According to Alexander Shulgin in his 1997 book TiHKAL, it is unknown whether 2-iodo-LSD has ever been tested in humans.

Pharmacology

Pharmacodynamics

2-Iodo-LSD shows high affinity for the serotonin 5-HT2 receptors and also shows affinity for other serotonin receptors as well as for the dopamine and adrenergic receptors. In contrast to LSD, but similarly to 2-bromo-LSD, 2-iodo-LSD is predominantly antagonistic at the serotonin 5-HT2A and 5-HT2C receptors and is described as non-hallucinogenic. The drug has about 57.4% of the antiserotonergic activity of LSD in the isolated rat uterus in vitro, whereas 2-bromo-LSD has about 103% of LSD's potency in this assay.

Radiolabeling

2-Iodo-LSD, a radiolabeled analogue of 2-iodo-LSD, has been used as a radioligand for serotonin 5-HT2 receptors. In addition, radiolabeled derivatives of 2-iodo-LSD, such as 1-methyl-2-iodo-LSD and 1-ethyl-2-iodo-LSD, have been developed for use as presumably non-hallucinogenic agents in imaging of serotonin receptors.

History

2-Iodo-LSD was described in the scientific literature by Albert Hofmann and colleagues by 1956.