Caffeine does not accumulate in the bloodstream or body and is normally excreted within several hours following consumption. In Chapter 3, you will learn that it can take up to 12 hours to detoxify a single cup of coffee. Evidence suggests that it may take up to 7 days to decaffeinate the blood of habitual coffee drinkers. It can take 3 weeks or more for the body's levels of stressful modes to return to normal if that's not accumulation.