Guaraná

Parts used and where grown

Guaraná is an evergreen vine indigenous to the Amazon basin. The vast majority of guaraná is grown in a small area in northern Brazil. Guaraná gum or paste is derived from the seeds and is used in herbal preparations.

Guaraná has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating

Health Concerns

Athletic performance

Fatigue

Weight loss and obesity

Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars

Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star

For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Historical or traditional use (may or may not be supported by scientific studies)

The indigenous people of the Amazon rain forest have used crushed guaraná seed as a beverage and a medicine. Guaraná was used to treat diarrhea, decrease fatigue, reduce hunger, and to help arthritis.¹ It also has a history of use in treating hangovers from alcohol abuse and headaches related to menstruation.

Active constituents

Caffeine and the closely related alkaloids theobromine and theophylline make up the primary active constituents in guaraná. Caffeine’s effects are well known and include stimulating the central nervous system, increasing metabolic rate, and having a mild diuretic effect.² One preliminary trial found no significant actions on thinking or mental function in humans taking guaraná.³ Guaraná also contains tannins, which act as astringents and may prevent diarrhea. However, this action has not been studied in human clinical trials.

How much is usually taken?

A cup of guaraná, prepared by adding 1/4–1/2 teaspoon (1–2 grams) of crushed seed or resin to 1 cup (250 ml) of water and boiling for ten minutes, can be consumed three times per day.⁴ Each cup may provide up to 50 mg of caffeine.

Are there any side effects or interactions?

As with any caffeinated product, guaraná may cause insomnia, trembling, anxiety, palpitations, and urinary frequency.⁵ Guaraná should be avoided during pregnancy and breast-feeding.

Are there any drug interactions?
Certain medicines may interact with guaraná. Refer to drug interactions for a list of those medicines.

References

1. Duke JA. CRC Handbook of Medicinal Herbs. Boca Raton, FL: CRC Press, 1985, 349.

2. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2d ed. New York: John Wiley & Sons, 1996, 293–4.

3. Galduroz JC, Carlini EA. The effects of long-term administration of guarana on the cognition of normal, elderly volunteers. Rev Paul Med 1996;114:1073–8.

4. Duke JA. CRC Handbook of Medicinal Herbs. Boca Raton, FL: CRC Press, 1985, 349.

5. Gruenwald J, Brendler T, Jaenicke C, et al. (eds). PDR for Herbal Medicines. Montvale, NJ: Medical Economics, 1998, 1017–8.

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The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over-the-counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires March 2005.