Allow 6-7 hours
is the most consumed stimulant
in the world, No sufficient research to encourage or discourage caffeine.
For the majority of healthy adults, consuming less than 400 mg of caffeine a day appears to be safe
the half life of caffeine (the time to get rid of half the caffeine in your system) is about 5-6 hours, so it depends on the initial dose of caffeine that you drank during the day