• Brazilian cocoa, caffeine, caffeine-tannin complex, Dark Dog Lemon®, elixir of youth, gift of the gods, Go Gum®, guarana bread, guarana gum, guarana paste, Guarana Rush®, guarana seed paste, guaranin, guaranine, Guts®, Happy Motion®, Josta®, mysterious Puelverchen, pasta guarana, Paullinia, Paullinia cupana, Paullinia sorbilis, Sapindaceae (family), Superguarana, tetramethylxanthine, Uabano, Uaranzeiro, Zoom®.

• Guarana is a native species of South America and has stimulating properties when taken by mouth. Guarana is also used to enhance athletic performance and to reduce fatigue. It has been used in the past as an aphrodisiac, diuretic, astringent, and to prevent malaria and dysentery, diarrhea, fever, headache, and rheumatism.
• The active ingredient in guarana was formerly called guaranine (tetramethylxanthine), but was later found to be caffeine. Guarana has one of the highest caffeine contents of all plants (up to 7%), and has been used by manufacturers for its caffeine content (e.g., Dark Dog Lemon®, Guts®, and Josta®).
• Although there is no scientific evidence that guarana itself increases mental alertness, its relationship to caffeine makes it probable that it would possess the same effects. It is proposed that the stimulatory effect of guarana is more gradual and sustained than caffeine due to the caffeine-tannin complex. Guarana is generally regarded as safe when not combined with other stimulatory agents, such as ephedra.

• Aphrodisiac, appetite suppressant, asthma, astringent, chronic diarrhea, cocaine withdrawal, dermatitis, diuretic, dysentery, enhanced athletic performance, fatigue, fever, flavoring agent, headache, heart conditions, lower back pain, malaria, migraine, platelet aggregation inhibition, rheumatism, skin conditions, stimulant, stress (heat), tonic (nerve).Studies have been performed with caffeine, a prominent constituent of guarana, for allergic rhinitis, apnea (pause in breathing) of prematurity, asthma, atopic dermatitis, bronchiectasis (a chronic lung disease), cancer, cardiac disorders, electroconvulsive therapy (a procedure in which an electric current is briefly applied to produce a seizure), exercise, exercise-induced bronchoconstriction, extubation (removal of the breathing tube), fecundability (monthly chance of pregnancy), fertility, fibromyalgia (chronic musculoskeletal disorder), headache, hyperactivity, hyperkinetic pediatrics, hypoglycemia (low blood sugar), kwashiorkor (severe malnutrition), migraines, minimal brain dysfunction, necrotizing enterocolitis (inflammatory disease effecting the intestinal tract), neuroleptic-induced catalepsy (rigidity of the extremities and by decreased sensitivity to pain), pain, Parkinson's Disease, postprandial hypotension (low blood pressure), post-surgery pain, seizure, sore throat, stroke, transcutaneous electrical nerve stimulation (TENS).

Adults (over 18 years old)

• There is no proven effective dose for guarana. Teas, capsules and energy drinks are all commercially available. For cognitive enhancement, a single dose of 150 milligrams guarana dry extract, standardized to 11-13% alkaloid concentration has been used. One gram of guarana up to four times a day has been taken to relieve diarrhea or dysentery. As a diuretic, 486 milligrams of guarana daily has been used. One to two tablets or capsules (200-800 milligrams guarana extract) before breakfast or lunch, not to exceed 3 grams daily, has reportedly been used for energy enhancement.

Children (under 18 years old)

• There is no proven safe or effective dose for guarana in children.

• This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

1. Berube-Parent S, Pelletier C, Dore J, et al. Effects of encapsulated green tea and Guarana extracts containing a mixture of epigallocatechin-3-gallate and caffeine on 24 h energy expenditure and fat oxidation in men. Br J Nutr 2005;94(3):432-436.
2. Boutroy MJ, Vert P, Monin P, et al. Methylation of theophylline to caffeine in premature infants. Lancet 4-14-1979;1(8120):830.
3. Cheraskin E, Ringsdorf WM, Jr. Blood-glucose levels after caffeine. Lancet 9-21-1968;2(7569):689.
4. Cole P. Coffee-drinking and cancer of the lower urinary tract. Lancet 6-26-1971;1(7713):1335-1337.
5. Debrah K, Sherwin RS, Murphy J, et al. Effect of caffeine on recognition of and physiological responses to hypoglycaemia in insulin-dependent diabetes. Lancet 1-6-1996;347(8993):19-24.
6. Fraumeni JF Jr, Scotto J, Dunham LJ. Coffee-drinking and bladder cancer. Lancet 11-27-1971;2(7735):1204.
7. Fukumasu H, Silva TC, Avanzo JL, et al. Chemopreventive effects of Paullinia cupana Mart var. sorbilis, the guarana, on mouse hepatocarcinogenesis. Cancer Lett. 5-7-2005;
8. Haller CA. Jacob P, Benowitz NL. Short-term metabolic and hemodynamic effects of ephedra and guarana combinations. Clin Pharmacol.Ther. 2005;77(6):560-571.
9. Hess AM, Sullivan DL. Potential for toxicity with use of bitter orange extract and guarana for weight loss. Ann.Pharmacother. 2005;39(3):574-575.
10. Jacobson MF, Goldman AS, Syme RH. Coffee and birth defects. Lancet 6-27-1981;1(8235):1415-1416.
11. James JE. Is habitual caffeine use a preventable cardiovascular risk factor? Lancet 1-25-1997;349(9047):279-281.
12. Joesoef MR, Beral V, Rolfs RT, et al. Are caffeinated beverages risk factors for delayed conception? Lancet 1-20-1990;335(8682):136-137.
13. Nyska A, Murphy E, Foley JF, et al. Acute hemorrhagic myocardial necrosis and sudden death of rats exposed to a combination of ephedrine and caffeine. Toxicol.Sci. 2005;83(2):388-396.
14. Roberts AT, Jonge-Levitan L, Parker CC, et al. The effect of an herbal supplement containing black tea and caffeine on metabolic parameters in humans. Altern Med Rev 2005;10(4):321-325.
15. Shapiro P. Caffeine for allergic rhinitis. Lancet 4-3-1982;1(8275):793.