An all-in-one pre-workout, the Optimum Nutrition Gold Standard Pre-Workout 30 Servings is formulated for your toughest workouts. It contains elements that are designed to optimize your energy production, focus, muscle growth, and concentration to ensure you make the most of your gym time. HOW IT WORKS: 375 mg of Acetyl-L-Carnitine HCI for energy production 250 mg of N-Acetyl-L-Tyrosine for focus and concentration Muscle Matrix including 25 mg of AstraGIN(R) to promote muscle growth 175mg caffeine, 1.5g beta alanine and 3 g creatine monohydrate Take one scoop 30 minutes before training for best results DETAILS Banned-substance tested 5 calories per serving Contains (30) servings Weight: 10.58 oz. Style: 2730504