- Stimulant-free - Improve muscular endurance and performance - Increase energy and focus - Increase vasodilation and blood flow for a big muscular “pump” and improved nutrient delivery   Pump Addict SF (Pump Addict Stim-Free) is perfect for coffee lovers or nighthawks. When you don’t need the added caffeine… but you want the crazy muscle pumps! SF has two key vasodilators (Citrulline and Agmatine) which increase blood flow, as well as improve nutrient and oxygen delivery to the muscle, but one of the other key ingredients that makes this such a special stim-free pre-workout is the Himalayan sea salt and potassium balance.