HTR2A
HTR2A 5-HT2A receptor — the molecular target that 1 compounds in the wiki act on.
In one line: The receptor psychedelics act on — linked to a burst of brain plasticity.
HTR2A (the 5-HT2A serotonin receptor) is the main dock for classic psychedelics like psilocybin. Activating it sets off a burst of neuroplasticity — the brain forming new connections — which, paired with therapy, is showing real promise for depression that hasn't responded to other treatments.
Full doses under supervision are where the strong evidence is; "microdosing" (tiny sub-perceptual doses) mostly performs no better than placebo in controlled trials, despite the hype.