Isotopic DMT as a Probe of Spin-Dependent Psychedelic Pharmacology

We propose a decisive experimental protocol to test the hypothesis that the psychedelic state involves the radical pair mechanism (RPM) operating at the serotonin 5-HT2A receptor. The key insight is that the psychedelic ligand itself — N,N-dimethyltryptamine (DMT, C12 H16 N2 ) — is the source of the hyperfine fields driving the singlet-triplet oscillation. By synthesizing isotopically labelled variants (13 C-DMT and 15 N-DMT), one selectively modifies the nuclear spins of the ligand atoms without altering the molecular geometry, charge, receptor affinity, or metabolic half-life. The Kinetic Isotope Effect (KIE), which dominates in deuterium substitution (∆m = +100%), is negligible for 13 C (∆m = +8%, KIE < 1.04) and 15 N (∆m = +7%, KIE < 1.03). Any observed change in psychedelic phenomenology under these substitutions constitutes direct evidence for the Magnetic Isotope Effect (MIE) — and hence for the RPM — at the heart of the conscious experience. We describe the synthesis, the behavioural assay (Head-Twitch Response in mice), the human protocol, and the predicted outcomes for each of four theoretical scenarios. This protocol provides the firstexperiment in which a cosmological algebraic framework (Cl(12, 2)) generates a falsifiable prediction in molecular pharmacology.