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Supplement Forms/Alternate Names:

Paullinia cupana, guaraná


Guarana is a vine that has long been used to flavor drinks. The seeds have been used to reduce fatigue, promote weight loss, and improve athletic performance. Guarana can be taken as a pill, powder, or extract. The seeds can also be eaten plain or made into a tea.


50 milligrams 1 to 2 times daily

What Research Shows

May Be Effective

  • Cancer Treatment Support —may ease fatigue when used with standard treatment A1-A5

Not Enough Data to Assess

  • Obesity B1
  • Psychological well-being C1

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe to take guarana in small doses for a short time, but increases in heart rate and blood pressure are possible.D1, D2 Guarana should not be taken in high doses. Not enough studies have been done to say whether it is safe to use for a long period. Women who are pregnant or breastfeeding should limit their intake to small doses at most.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse such as:

  • People with depression should talk to their doctors before taking guarana. It may interact with their medicine.


A. Cancer Treatment Support

A1. da Costa Miranda V, Trufelli DC, et al. Effectiveness of guaraná (Paullinia cupana) for postradiation fatigue and depression: results of a pilot double-blind randomized study. J Altern Complement Med. 2009 Apr;15(4):431-433.

A2. de Oliveira Campos MP, Riechelmann R, et al. Guarana (Paullinia cupana) improves fatigue in breast cancer patients undergoing systematic chemotherapy. J Altern Complement Med. 2011;17(6):505-512.

A3. Leggett S, Koczwara B, et al. The impact of complementary and alternative medicines on cancer symptoms, treatment side effects, quality of life, and survival in women with breast cancer--a systematic review. Nutr Cancer. 2015;67(3):373-391.

A4. Sette CVM, Ribas de Alcântara BB, et al. Purified Dry Paullinia cupana (PC-18) Extract for Chemotherapy-Induced Fatigue: Results of Two Double-Blind Randomized Clinical Trials. J Diet Suppl. 2018 Sep 3;15(5):673-683.

A5. Pereira PTVT, Reis AD, et al. Dietary supplements and fatigue in patients with breast cancer: a systematic review. Breast Cancer Res Treat. 2018 Oct;171(3):515-526.

B. Obesity

B1. Boozer CN, Nasser JA, et al. An herbal supplement containing Ma Huang-Guarana for weight loss: a randomized, double-blind trial. Int J Obes Relat Metab Disord. 2001;25(3):316-324.

C. Psychological Well-Being

C1. Silvestrini GI, Marino F, et al. Effects of a commercial product containing guaraná on psychological well-being, anxiety and mood: a single-blind, placebo-controlled study in healthy subjects. J Negat Results Biomed. 2013 May 25;12:9.

D. Safety

D1. Cohen PA, Ernst E. Safety of herbal supplements: a guide for cardiologists. Cardiovasc Ther. 2010 Aug;28(4):246-253.

D2. Jalili J, Askeroglu U, et al. Herbal products that may contribute to hypertension. Plast Reconstr Surg. 2013 Jan;131(1):168-173.

Last reviewed March 2020 by EBSCO NAT Review Board Eric Hurwitz, DC  Last Updated: 6/22/2020