The first time I took it i took 1 scoop and it did nothing. Second time I took 3, I felt excited for the gym, but I've done that before without taking jack3d- listening to music, watching Arnie vids on youtube. Had a TERRIBLE crash though. Felt to sad and tired.
Not worth it. Have a sugar free redbull or if you're taking creatine have a normal redbull and creatine (need to take creatine with sugary things) and watch a ulysses video or something on youtube and you'll get just as psyched without the shit come down.
and yes, empty stomach is best. Even if you don't take jack3d, you shouldn't eat a meal within 30 minutes of a workout because when you eat blood goes to your stomach/intestines to digest food when you need it to go to your muscles. Same with eating after a workout, except for your post workout shake, don't eat for like an hour.