I've been using MRI's Black Powder, a pre-workout nitric oxide booster, for about a month now and like it. It has a 202mg blend of caffeine, green tea extract and betaine-anhydrous. So i'm assuming it has about 100-150mg of caffeine. I just bought Hydroycut to lose fat. It has 300mg of caffeine per serving and it says to take two servings a day, so 600mg! I've already cut out coffee, soda and chocolate from my diet, but i still have the occasional soda here and there. even without anything in my diet that's still 700-750mg of caffeine on workout days (4-5 days a week). Is that an unhealthy amount? most websites say not to exceed 300mg. In case it matters, I'm 19 years old, 6'1 and 210lbs.