Definition Day: 5-HT2A Receptor & Microdosing
Two more terms that come up constantly and rarely get explained plainly.
5-HT2A Receptor: the single receptor that psilocybin, LSD, DMT, and mescaline all act on as agonists, despite looking chemically quite different from each other. It's also why an antagonist at the same receptor can block a trip outright — see our Antagonist entry in the Encyclopedia. Definium's LSD-derived DT120 works through this exact receptor; we've covered where that drug and its patents stand.
Microdosing: taking a sub-perceptual dose, too small to produce a noticeable trip. The open-label, self-report evidence is enthusiastic. The rigorous evidence isn't there yet — a 2026 microdosed-LSD depression trial we covered looked strong with no control group, then failed to beat an active placebo once one was added. A useful reminder that open-label results and controlled results can point in opposite directions for the same compound.
Full entries, plus 140 other terms, are in our Encyclopedia.