The old rules are crumbling. Substances that once lived exclusively in warehouses, festivals and police evidence bags are now being administered in private clinics with leather recliners, noise-cancelling headphones and consultants in white coats. MDMA, ketamine and psilocybin are...

The first punch hit like a sledgehammer—a bare-knuckled jab that snapped my head back and sent a jolt of pain radiating through my jaw. My vision blurred, the basement’s dim lights streaking into hazy lines. My opponent, a lean...