Here's something surprising: even if the FDA (the US drug regulator) officially approves psilocybin as a medicine, that doesn't automatically make it legal to prescribe or use. The DEA (the federal drug enforcement agency) runs a completely separate review process to decide what 'schedule' — meaning legal category — a drug belongs to, and that process is slow and cautious. So there could be a gap where psilocybin is technically FDA-approved but still federally illegal to distribute.
Scheduling is a separate, evidence-heavy administrative process. Law enforcement caution outweighs clinical momentum in my division's calculus.