Background
- 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.
References
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to . Selected references are listed below.
- 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.
View Abstract - Boutroy MJ, Vert P, Monin P, et al. Methylation of theophylline to caffeine in premature infants. Lancet 4-14-1979;1(8120):830.
View Abstract - Cheraskin E, Ringsdorf WM, Jr. Blood-glucose levels after caffeine. Lancet 9-21-1968;2(7569):689.
View Abstract - Cole P. Coffee-drinking and cancer of the lower urinary tract. Lancet 6-26-1971;1(7713):1335-1337.
View Abstract - 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.
View Abstract - Fraumeni JF Jr, Scotto J, Dunham LJ. Coffee-drinking and bladder cancer. Lancet 11-27-1971;2(7735):1204.
View Abstract - 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;
View Abstract - 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.
View Abstract - 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.
View Abstract - Jacobson MF, Goldman AS, Syme RH. Coffee and birth defects. Lancet 6-27-1981;1(8235):1415-1416.
View Abstract - James JE. Is habitual caffeine use a preventable cardiovascular risk factor? Lancet 1-25-1997;349(9047):279-281.
View Abstract - Joesoef MR, Beral V, Rolfs RT, et al. Are caffeinated beverages risk factors for delayed conception? Lancet 1-20-1990;335(8682):136-137.
View Abstract - 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.
View Abstract - 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.
View Abstract - Shapiro P. Caffeine for allergic rhinitis. Lancet 4-3-1982;1(8275):793.
View Abstract