Got this stuff back when it was 5150. Helped through my first year of a job with crazy hours (both time and shift length). Mixed it with OJ and it did the job just right! Make sure you dilute it but I say that not so much because of the slight bitter taste but rather the caffeine needs plenty of water to go through your bloodstream effectively. The only energy drink that could touch it was Cocaine (the actual energy drink, not the drug).