Raw Pump Non-Stim PreworkoutPump is a versatile pre training formula that can be stacked or taken solo. This non stimulant pre workout comes in clutch for the night owls who enter the iron dungeon late into the day and must avoid caffeine in order to get a good night's rest. On the other hand, Pump can be stacked with your favorite pre workout in order to enhance the effects and maximize blood flow to deliver maximum nutrients to working muscle groups.