Living document, last updated: 2026-08-14 Tim Ferriss shared a quote from Roland Griffiths, a leading researcher on caffeine: “You can never understand your relationship to a drug, to a psychoactive substance, unless you get off it and stand back and look at it.” Ferriss’s conversation with Griffiths, in turn, inspired an experiment where Ferriss wentContinue reading “Why “No Caffeine After 2 PM” Fails Heavy Coffee Drinkers & What Actually Works”