Psilocybin: what the dose does, and what it does not

Psilocybin is a tryptophan-derived prodrug: the body converts it to psilocin, which acts mainly on serotonin 2A receptors. It does not force a serotonin dump the way MDMA does, which is why the aftermath looks nothing alike.

The experience. Onset is slow (20 to 60 minutes, longer on a full stomach), the main experience runs about four to six hours, and a gentle tail follows. What changes with the dose is not just intensity but kind: low doses lift mood and sharpen the senses, moderate doses bring emotional and perceptual depth, and high doses can dissolve the ordinary sense of self entirely.

The real risks. The physical risk profile is mild. The psychological risk is real, and so is the risk of a bad decision in an unsafe place. The things that actually cause harm are an unknown batch, an impatient redose, the wrong setting, and a short list of medication interactions.

The aftermath. There is no serotonin-depletion comedown to recover from, and importing MDMA's "Tuesday blues" framing here gets it wrong. What people do report is tiredness, disrupted sleep for a night or two, emotional rawness, and sometimes lingering anxiety or derealisation that is worth taking seriously if it does not settle. Recovery is mostly sleep, food, quiet, and making sense of what happened.

Tolerance. It builds fast and cross-tolerates with other classic psychedelics. Two days running and the second day is markedly weaker. It resets over roughly one to two weeks, which enforces the spacing these experiences want anyway.

Educational only. Threshold does not sell, supply, or encourage drug use. The lowest-risk option is not to use.