Can Guarana Boost Your Energy?

Glass of Guarana Energy Drink

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Guarana (Paullinia cupana) is a plant native to northern Brazil and other regions of the Amazon, originally cultivated as a medicine plant by the Sateré-Mawé people of Brazil, who continue to lead the way in sustainable harvesting of this plant through their product, warana. Said to fight fatigue, boost mental alertness, and promote weight loss, guarana is often also found in popular sodas and energy drinks, such as Red Bull and Monster. A seed paste, syrup, or extract is made from the guarana plant and then added to these drinks. In Brazil, guarana drinks and are considered health "tonics" and are almost as popular as traditional cola-based sodas.

The fruit contains caffeine-rich seeds which have up to three times the amount of caffeine as coffee beans. The seeds are also rich in tannins and the stimulants theophylline and theobromine.

Health Benefits

Decreased Fatigue

A 2011 study of breast cancer patients undergoing systemic chemotherapy and a 2018 study of patients with chronic kidney disease found that patients taking guarana experienced significantly reduced fatigue compared with those taking a placebo. The study in breast cancer patients used a 50 mg dose twice daily, and the study in patients with chronic kidney disease examined the effects of doses as high as 200 mg and 400 mg, indicating anti-fatigue effects at low and high doses. Additionally, antioxidant effects of guarana extracts have been observed in pre-clinical trials, according to a review published in 2018. According to one study, oxidative stress shows promise as a potential biomarker for chronic fatigue syndrome.

Improved Cognition

A randomized, double-blind crossover study assessed cognitive performance with a go/no-go task in fifty-six participants after they had ingested either a multi-vitamin-mineral preparation supplemented with 300 mg guarana, a caffeine supplement, or a placebo supplement. It was found that responses were faster on the go/no-go task without a change in accuracy between 30 and 90 mins after ingesting the guarana. A significant decrease in heart rate variability was observed during the first hour after taking the caffeine, yet remained stable after taking guarana, suggesting guarana may be able to improve decision-making performance without destabilizing autonomic nervous system regulation during the first hour as much as caffeine.

Another double-blind, placebo-controlled study of guarana use throughout the day found that guarana improved secondary memory performance, mood, and alertness at low (37.5 mg, 75 mg) and higher (150 mg, 300 mg) doses, with the lower doses being more effective. While this data is promising for acute uses, a study examining the use of guarana, caffeine, and placebo on the cognition of 45 older individuals and found no significant lasting effects of guarana on cognition long-term.

Weight Loss

Guarana supplement manufacturers sometimes claim that guarana is helpful for promoting weight loss, however there is not a lot of clinical research to support this claim. It is possible proponents are relying on data from a 2001 study, a randomized, double-blind, placebo-controlled trial that examined the effects of 240 mg/day guarana, as a caffeine source, combined with 72 mg/day Ma Huang, containing ephedrine alkaloids. Over the 8 weeks of treatment, this combination led to a significantly greater loss of weight and fat as well as larger reductions in hip circumference and serum triglyceride levels as compared with placebo.

These effects cannot be attributed to the guarana alone, and eight of the study participants quit the study early as a result of unwanted side-effects, insomnia and headache being among the most frequently reported. An animal study from 2005 examined the effect of 14 days of guarana supplementation on fat metabolism in sedentary and trained rats and found a fat-burning effect attributable to the caffeine content, but more research is needed.

Possible Side Effects

Guarana contains a large amount of caffeine, and the precise amount may not be properly documented on the label. Side effects can include those common to many stimulants: stomach irritation, increased heart rate and blood pressure, and nervousness or agitation. A 2018 study of patients with chronic kidney disease found that incidents of headaches, insomnia, gastric discomfort, nausea and vomiting were highest in the group taking 400 mg per day.


The caffeine content of guarana differ from product to product. Since many doctors recommend limiting caffeine during pregnancy and breastfeeding and it isn't possible for consumers to accurately estimate how much caffeine they are consuming, it would be best to avoid taking guarana during pregnancy or while breastfeeding.


If you are sensitive to caffeine or xanthines or have heart problems, high blood pressure, an overactive thyroid, an anxiety disorder, insomnia, or epilepsy, you should talk with your healthcare provider before taking guarana. Patients that can be harmed from the stimulating properties of guarana were excluded from at least one clinical trial, as were those taking antidepressants, anxiolytics, or sleeping pills, with which the effects of guarana might interfere.

Known Interactions

Combining guarana with other stimulants like yerba mate, diet aids, or performance-enhancing supplements may lead to palpitations, arrhythmias, high blood pressure, seizures, and other adverse effects.

Combining guarana with ephedra or Ma-Huang may increase the risk of stroke, hemorrhage, myocardial infarction, and sudden death, and has been associated with increases in heart rate, blood pressure, and potentially harmful changes in glucose and potassium levels. 

Guarana has been found to decrease platelet aggregation and thromboxane synthesis, so it may increase the risk of bleeding when taken with aspirin, anticoagulants such as warfarin (Coumadin®), and platelet inhibitors such as ticlopidine (Ticlid®), clopidogrel (Plavix®).

Guarana should also not be combined with alcohol or MAO-inhibitors as combining these with caffeine may cause encephalopathy, neuromuscular irritability, hypotension, or sinus tachycardia, though this has not been well studied in patients taking guarana specifically.

Make sure to learn about ​using supplements safely.

Dosage and Preparation

A dose of 70g guarana powder is on the lower end for available supplements, but is all you really need to get the benefits, which may actually lessen at the higher doses, though if you are seeing continued benefits without side effects, there is not research to suggest an issue with repeating dosing several times throughout the day. Typically, guarana supplements are prepared by preparing an extract from the seeds or grinding the seeds into a powder.

Industrial processing method for guarana seeds may increase the presence of polycyclic aromatic hydrocarbons, a group of chemical carcinogens that have also been associated with pulmonary, gastrointestinal, and dermatologic side effects.

What to Look For

The popular energy drinks Full Throttle, Monster, Red Bull, and Rockstar all contain guarana, but are marketed as conventional beverages, not as dietary supplements, and are not the healthiest or most sustainable ways to get the benefits.

The highest degree of quality control for guarana supplements can be found in those made by the Sateré-Mawé people of Brazil. The Sateré-Mawé formulation is called warana and can be identified by a packaging label indicating certification by the International Analog Forestry Network. Warana can be purchased online through Artisans du Monde, a French network of local fair trade associations.

Other Questions

What is the relationship between the Sateré-Mawé and the guarana plant?

Guarana plays an important role in the mythology of the Sateré-Mawé people of Brazil, for whom the word guaraná translates to "the beginning of all knowledge." The Mawé were the first to cultivate guarana for use as a medicinal and the seeds are a foundation of their economy.

The rising popularity of guarana worldwide and the competitive pressure of commercial growers from abroad has led to the decline of the guarana population and traditional methods of cultivation. The Slow Food Foundation for Biodiversity recognizes the guarana plant as endangered and the industry as a threat to Mawé bio-cultural survival.

Are most guarana supplements sustainably harvested and fair trade?

Unfortunately, no. In 2006, the Consortium of Sateré-Mawé Producers (CPSM), part of the General Council of the Sateré-Mawé Tribe (CGTSM), the Sateré-Mawé's largest body of political representation, began a project to obtain protected status for the guarana plant, called The Presidia, designed to preserve traditional methods of cultivation, harvesting, and consumption.

You can buy guarana powder from plants that have been sustainably harvested through traditional methods by the Consortium of Sateré-Mawé Producers by looking for the brand name warana. Fewer than two tons of warana are put up for sale per year, however, and the Sateré-Mawé are not the source of most guarana supplements on the market.

If you want to help, you can reach out to the manufacturer of your favorite guarana product. Ask them about their harvesting methods, and what they are doing to protect and support the originators of this ecological knowledge. This could go along way towards promoting the adoption of more sustainable harvesting methods and protections for the Sateré-Mawé.

Is there a best time of day to drink a guarana supplement?

One manufacturer recommends drinking guarana 15 minutes prior to a planned activity in order to receive maximum benefits to focus. There is no absolutely "right" or "wrong" time of day to drink guarana, however you may find it harder to sleep if you drink it within 6 hours of bed time.

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