GUARANA Guarana (Paulinnia cupana) is a very popular herb among the Brazilian population, who drink it as coffee. In Japan it is used as a medicine and in France it is sold as a diet-product. Guarana powder contains about 4.2% caffeine. The caffeine in guarana is assimilated better and more evenly by the body than the caffeine in coffee. Guarana is an energizer. In combination with ephedra it enhances the effect of ephedra in a positive way.