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):
and relatively consistent scientific data showing a substantial health benefit.
Contradictory, insufficient, or preliminary studies
suggesting a health benefit or minimal health benefit.
For an herb, supported by traditional use but minimal
or no scientific evidence. For a supplement, little scientific support and/or minimal health
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.
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
Certain medicines may interact with guaraná. Refer to drug interactions for a list of those medicines.
References (To view, roll mouse over the "References" heading; to hide, click on the heading)
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,
3. Galduroz JC, Carlini EA. The effects of long-term administration of
guaraná on the cognition of normal, elderly volunteers. Rev Paul Med
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.
The information presented in Aisle7 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