Guarana (Paullinia Cupana) is a climbing shrub that grows wild in the Amazon regions of Brazil and Uruguay. Most modern commercial Guarana is grown on government plantations where the highest quality plants are harvested.
The Guarana fruit is havested when ripe, after turning a bright red or yellow. The gathered fruit yields a small round black seed which is crushed to form a paste containing 10% Guaranine (caffeine).
Guarana has been used for hundreds of years by Brazilian Indians as a general tonic for the body and as a source of energy. Guarana acts on the central nervous system to prevent fatigue and break down lactic acid from muscle stress.
Besides caffeine, Guarana contains a host of other xanthines. Theobromine and Theophylline are the primary xanthines, acting as muscle relaxants and possessing diuretic properties.