But the caffeine doesn’t stop there. It also stimulates the production of adrenaline. You know, the fight or flight hormone? This increases your heart rate, gets your blood pumping, and even opens up your airways. Furthermore, it affects Dopamine levels by preventing its reabsorption in the brain, which makes you feel happy. In fact, this is the exact same thing that cocaine does, just to a lesser degree. It’s a drug, after all. This dopamine stimulation is also aspect of coffee that makes it moderately addictive. So can you drink too much coffee? It turns out there is lethal dose of caffeine which is somewhere around 150 mg of caffeine per kilogram of your body. This means if you weight 70 kg you would require 140000 mg of caffeine to overdose. Put into perspective, an average cup of coffee contains roughly 150 mg of caffeine, meaning if you are 70 kg, approximately 70 cups of coffee would kill you. However, you’d have to drink those cups all at once making it effectively impossible to overdose on caffeine from coffee, since you wouldn’t be able to physical fit that much in your stomach.