(R)-70
-70, or R-70, is a non-hallucinogenic selective serotonin 5-HT2 receptor moderate-efficacy partial agonist of the tetrahydropyridinylpyrrolopyridine family related to the psychedelic tryptamines. It shows preference for activation of the serotonin 5-HT2A receptor of about 6.4-fold relative to the serotonin 5-HT2B receptor and of about 30-fold relative to the serotonin 5-HT2C receptor. The drug is a biased agonist of the serotonin 5-HT2A receptor, activating Gq protein signaling more readily than β-arrestin2 signaling. It did not significantly produce the head-twitch response in mice, but did produce antidepressant-like effects. -70, along with its close analogue (R)-69, was first described in the scientific literature by Bryan L. Roth and colleagues in 2022. It was identified via an ultra-large-scale docking campaign for the serotonin 5-HT2A receptor.