Took this while working out twice a week, worked out hard for 4-5 hours at the gym muscle building and weight lifting, I dropped 40 pounds and packed on muscle, nearly tripped what I could do before starting. Only issue i had with this stuff was the short temper my friends and I called it "Roid rage" You will have a very short temper. But if you can control your emotions and arent 13 you can handle it.