With optimal electrolytes caffeine and b vitamins nuun boost keeps you hydrated and gives you a boost when you need it most nuun boost contains caffeine from green tea extract b vitamins and their signature blend of optimal electrolytes nuun boost contains clean ingredients and is low in calories and sugar the caffeine helps to give your energy a lift and b vitamins help your body to metabolize fuel efficiently to keep energy high with the same optimal electrolyte level you know and tr