(R)-69 (3IQ) is a drug of the tetrahydropyridinylpyrrolopyridine family related to the psychedelic tryptamines which acts as a 5-HT<sub>2A</sub> receptor agonist, with 4.6-fold selectivity over 5-HT<sub>2B</sub> and 49-fold selectivity over 5-HT<sub>2C</sub>. It has a 5-HT<sub>2A</sub> K<sub>i</sub> of 680 nM and an EC<sub>50</sub> of 41 nM. (R)-69 is a biased agonist selective for activation of the G<sub>q</sub> coupled signalling pathway, with much weaker activation of the ò-arrestin 2 coupled pathway. In animal studies it produces antidepressant-like activity but without producing the head-twitch response associated with psychedelic effects. The drug was identified along with its close analogue (R)-70 via an ultra-large-scale docking campaign against the serotonin 5-HT<sub>2A</sub> receptor and was first described by Bryan L. Roth and colleagues in 2022. A number of related derivatives have also been developed.