Do You Have a Tolerance to Coffee?

There are no strong clinically significant adverse effects of being on caffeine the way there is with other harsher chemicals like cocaine and heroin. You can build up a tolerance to caffeine, which isn't the same as an addiction. The Food and Drug Administration suggests a max of 400 milligrams of caffeine a day for the average person. Most sources say that's roughly the amount of caffeine in four cups of coffee.