Guarana Go Energy Boost Drink 300gProduct description: Guarana is a plant. It is named for the Guarani tribe in the Amazon, who used its seeds to brew a drink. Today, guarana seeds are still used as medicine. People take guarana for weight loss, athletic performance, mental performance and to increase energy. Guarana contains caffeine. Caffeine works by stimulating the central nervous system (CNS), heart, and muscles. Guarana also contains theophylline and theobromine, which are