So how much caffeine would it take to kill you? Thus, as you might expect, we couldn’t find any studies that show what amount of caffeine would definitively kill your average human. Although that might not sound like that much, in terms of raw amount of caffeine, it should be noted that that’s the amount of caffeine in about 1,200 cups of coffee! So this all might have you wondering how caffeine actually manages to kill? In toxic doses, caffeine can cause extremely low blood pressures, seizures, cardiac rhythm problems, and lactic acidosis.