Don't. One of my friends went up to 1.5g/day (using crystalline caffeine). After he had to give it up, he spend at least 6 months without energy, lethargic, slu

Don't. One of my friends went up to 1.5g/day (using crystalline caffeine). After he had to give it up, he spend at least 6 months without energy, lethargic, sluggish, possibly depressed. After ceasing typical consumption brain goes back to normal in 1-2 weeks. But for huge doses it might be not the case. (BTW: If anyone knows more info on the length of caffeine withdrawal as a function of does, I would be grateful!)