You Develop a Tolerance in Just Weeks
Caffeine dependence starts out innocuous enough. Maybe it's the end of the day and you need a little extra spark for that dinner date? Or perhaps you stayed up too late the night before and are reeling in your seat at work by lunchtime? But pretty soon, you find yourself comatose in the morning before slurping down that four-dollar A.M. Starbucks. That escalated rapidly...
"[Caffeine] is a stimulant, so it does increase metabolism," Yale neuroscientist Steven Novella remarked. "But actually you get tolerant to that effect very quickly. It takes only three weeks to get tolerant to the stimulative effect of caffeine, after that you're just basically staving off your caffeine withdrawal."
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