GM-2040

GM-2040 is a putatively non-hallucinogenic serotonin 5-HT_2A receptor agonist which was developed by Gilgamesh Pharmaceuticals. It is a partial agonist of the serotonin 5-HT_2A receptor, with a K_i of 3.4 nM, an EC₅₀Tooltip half-maximal effective concentration of 43.8 nM, and an E_maxTooltip maximal efficacy of 71.1%. Relative to the serotonergic psychedelic DOPR, the drug only weakly produces the head-twitch response (HTR), a behavioral proxy of psychedelic effects, in rodents, and hence may not produce hallucinogenic effects in humans. On the other hand, GM-2040 shows robust and persistent antidepressant-like effects in rodents.