It might seem like that but I’ve seen it recommended by doctors more than once. Caffeine stays in our system longer than most expect.

According to the FDA, the half-life of caffeine — the time it takes for the starting amount of the substance to reduce by half — is between four and six hours. This means that up to six hours after drinking a caffeinated beverage, half of the caffeine you consumed is still present in your body — keeping you alert. And, if it’s bedtime, potentially keeping you from falling or staying asleep.