Fig. 4: EEG power spectrum analysis illustrating the effects of 5-MeO-DMT on Delta (1–4 Hz), Theta (4–8 Hz), and Alpha (8–12 Hz) frequencies across different dosage groups.

The x-axis represents frequencies (0–15 Hz), and the y-axis indicates power levels. Each spectrum reflects a 4-s signal duration, displaying data from 21 EEG channels at two time points: before (Time: 0 min) and 15 min after administration (Time: 15 min). A, B In the placebo group, the power spectrum at Time 0 shows a prominent peak in the alpha frequency range, consistent with resting-state EEG activity. This peak remains robust 15 min post-administration, indicating typical alpha wave behavior with eyes closed. C, D (6 mg group), E, F (9 mg group), and G, H (12 mg group): At Time 0, before 5-MeO-DMT administration, each group shows a well-defined alpha peak similar to the placebo. However, 15 min post-dose, the alpha activity is markedly suppressed in all three dosage groups, with the degree of suppression increasing with higher doses. This attenuation of alpha waves suggests a dose-dependent suppression effect induced by 5-MeO-DMT. Although, these panels represent individual patient data, similar trends of alpha wave suppression were observed consistently across patients within each dosage group, reinforcing the specific impact of 5-MeO-DMT on alpha frequency activity.