Metabolic Nutrition ESP Pre-Workout | 500mg Caffeine. Metabolic New Pre-Workout ESP. Metabolic Nutrition is releasing a brand new Pre-workout formula called ESP. ESP is a pre-workout that comes in multiple flavors and uses a pre-workout proprietary blend. This new pre-workout is sure to get you all pumped and energized for your workout and we are going to sell it as soon as it is released!