For most people, 3-6 mg/kg of caffeine will give you that consistent, reliable boost you're looking for. But, if you're already moderately adapted to caffeine and looking to maximize your performance, 8 mg/kg can be where you hit that peak effect. Now, keep in mind, once you start pushing beyond that—like around 9 mg/kg—the chances of experiencing side effects really ramp up. So, do you need that much caffeine? Probably not. But if you can handle it and have a specific goal or performance issue you’re trying to overcome, then 6-8 mg/kg can have its place. I've linked a video below explaining the dose—fascinating stuff.