Guaraná (Paullinia cupana, syn. P. crysan, P. sorbilis) is a climbing plant in the maple family, Sapindaceae, native to the Amazon basin and especially common in Brazil. Guarana features large leaves and clusters of flowers, and is best known for the seeds from its fruit, which are about the size of a coffee bean. As a dietary supplement, guarana is an effective stimulant: its seeds contain about twice the concentration of caffeine found in coffee seeds (about 2–4.5% caffeine in guarana seeds compared to 1–2% for coffee seeds).
Since it contains a large percentage of Caffein, so this can be used for certain forms of sick head ache. Guarana is used for weight loss, to enhance athletic performance, as a stimulant, and to reduce mental and physical fatigue. It is a frequent addition to energy and weight loss products.
Some people also use it to treat low blood pressure and chronic fatigue syndrome (CFS), and to prevent malaria and dysentery. It is also used to enhance sexual desire, to increase urine flow, and as an astringent.
Other uses include treatment of ongoing diarrhea, fever, heart problems, headache, joint pain, backache, and heat stress. It has been used in the past as an aphrodisiac, diuretic, astringent, and to prevent malaria and dysentery, diarrhea, fever, headache, and rheumatism.
Preliminary research has shown it may affect how quickly the body perceives itself to be full. One study showed an average 5 kg (11 lb) weight loss in a group taking a mixture of yerba mate, guarana, and damiana, compared to an average one-pound loss in a placebo group after 45 days. Although inconclusive about specific effects due only to guarana, this study differs from another showing no effect on body weight of a formula containing guarana.
Guarana extract reduced aggregation of rabbit platelets by up to 37 percent below control values and decreased platelet thromboxane formation from arachidonic acid by 78 percent below control values.