What is caffeine's primary metabolite, and what percentage does it account for?	Paraxanthine (1,7-dimethylxanthine), accounting for ~80% of caffeine metabolism.
Why is the commonly cited 5-6 hour half-life of caffeine misleading?	It describes the conversion of caffeine into its metabolites, not elimination. The primary metabolite (paraxanthine) is more potent than caffeine and has its own half-life.