Guarana: Everything You Need to Know
Guarana is a native Amazonian plant from the soapberry family called Sapindaceae. Its scientific name is Paullinia cupana (P. cupana).
Guarana contains caffeine and other similar chemicals, such as theophylline and theobromine, can stimulate the central nervous system, heart, and muscles and may contribute to how guarana works.
Various health benefits are associated with consuming guarana, such as antioxidant effects, anti-cancer properties, and the capacity to boost heart health and brain health, making guarana a valuable, globally used dietary supplement.
This article discusses what you should know about guarana—including the evidence behind its health claims, potential side effects and interactions with other drugs and supplements, and additional safety information.
Explainer
Dietary supplements are not regulated in the same way drugs are in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. Choose a supplement tested by a trusted third party, such as the U.S. Pharmacopeia (USP), ConsumerLab.com, or NSF.org, whenever possible.
However, even supplements that are third-party tested are not necessarily safe for all or effective in general. Therefore, talking to your healthcare provider about any supplements you plan to take and checking in about potential interactions with other supplements or medications is important.
Supplement Facts
Active Ingredient(s): Caffeine, theophylline, theobromine
Alternate Names(s): Guarana, Paullinia cupana, P. cupana, Brazillian cocoa, cacao Brésilien, guarana seed extract, guaranine, zoom
Legal Status: Food, substances added to food, and dietary supplement
Suggested Dose: May vary based on the dosage form and medical condition
Safety Considerations: Possible side effects, interactions, and special considerations for children, in pregnancy, and while breastfeeding
Uses of Guarana
Explainer
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.
While additional research is necessary regarding effectiveness, people generally use guarana to treat various health conditions.
Research is most robust for the following:
Antioxidant Effects
A review article analyzed a small clinical trial in which healthy participants took 3 grams (g) of guarana daily. This short-term study's results suggested that guarana lessened the damage from free radicals (unstable atoms made during normal cell metabolism). As a result, guarana may have some antioxidant effects.
In general, antioxidants attack free radicals. Free radicals can damage components and systems within the body, including the hereditary material DNA.
Since this was a small and short-term study, further extensive research with more significant and longer-term clinical trials is necessary to assess guarana's effects better.
Brain Health
A review article showed that guarana helped with memory, attention, alertness, and reaction time.
While the results were positive, some studies combined guarana with vitamins, minerals, other dietary supplements, and exercise.
For this reason, it might be challenging to quantify guarana's effects. Future high-quality clinical trials should study more standardized guarana products and dosages.
Cancer
Cancer and its treatments usually come with various side effects.
Several clinical trials have supported guarana in relieving some side effects that arise as a result of having cancer or cancer-targeted treatment:
Drowsiness and sleepiness
Fatigue (excessive tiredness)
Poor appetite
Sleeping problems
Weight loss
Although promising, more clinical trials are warranted, as guarana seemed to have positive results in people with only certain types of cancer.
Heart Health
One study in a review article observed the effects of drinking guarana at least twice weekly in older adults.
Per the results of the study, consuming guarana was associated with fewer side effects and decreased disease severity as a result of preexisting metabolic syndrome (a group of medical conditions that increases your risk of heart disease).
While the results are promising, additional research with high-quality clinical trials is still needed to quantify further to what extent guarana lessens the effects of metabolic syndrome.
What Are the Side Effects of Guarana?
As with many medications and natural products, guarana can have side effects.
Common Side Effects
Common side effects of guarana include:
Stomach upset
Severe Side Effects
Severe side effects are possible, especially with large doses of guarana.
Examples of severe side effects include:
Serious allergic reaction: A severe allergic reaction is a profound side effect possible with any medication or natural product. If you're having a severe allergic reaction, your symptoms may include breathing difficulties, itchiness, and rash.
Abnormal heart rhythm and rate: Large amounts of guarana may look similar to a caffeine overdose with symptoms of heart arrhythmia (abnormal heart rhythm and rate).
If you're having a severe allergic reaction or if any of your symptoms feel life-threatening, call 911 and get medical help right away.
Precautions
A healthcare provider may advise against guarana use if any of the following applies to you:
Severe allergic reaction: Avoid guarana if you have a known allergy to it or other ingredients or parts of the supplement. If you need clarification on whether it's safe, ask a registered dietitian, pharmacist, or healthcare provider for more information.
Pregnancy: Guarana is a plant with a high caffeine content. Generally, caffeine may raise your heart rate, blood pressure, and the amount of urine you make.
Other potential effects are tremors, indigestion, light-headedness, nausea, and sleeping problems. While pregnant, you might be more sensitive to these effects.
As for the impact on the unborn fetus, there is conflicting information about caffeine's effects on miscarriages, preterm births, and low birth weights.
But adverse effects are unlikely with daily caffeine amounts of 300 milligrams (mg) or less than one to two cups of coffee daily.
Since additional research on guarana is needed, contact a healthcare provider to discuss the benefits and risks before using guarana during pregnancy.
Breastfeeding: Guarana is a source of caffeine. For this reason, guarana will likely have similar effects as caffeine on nursing infants.
For example, 10 cups of coffee per day from a breastfeeding parent might be too much for a nursing infant. The breastfeeding infant may experience fussiness, tremors, and sleeping problems at these high amounts of caffeine. And more than 450 milliliters (mL) of coffee per day can reduce iron levels in breast milk, increasing the chances of low iron levels and anemia in nursing infants.
In general, try to limit the amount of coffee to a maximum of 300 to 500 mg, or five cups of coffee per day. These amounts are likely safe for babies at least 3 weeks old. But preterm and newborn infants tend to clear out caffeine slower.
Therefore, be sure to use guarana with caution. Before you use guarana, contact a healthcare provider to discuss the benefits and risks.
Adults over age 65: Older adults participated in some guarana-related studies. In general, however, more rigorous research on guarana is still needed.
Moreover, older adults are generally more likely to have medication side effects than younger people. For this reason, people in this population should use caution with guarana.
Children: Children may get caffeine from various sources, such as plant-based foods and drinks—like guarana.
According to a systematic review (a methodical review of a collection of studies), caffeine may have positive and negative effects on children. Positive ones may include supporting brain function and athletic performance. But caffeine may adversely affect their sleep pattern, weight gain, growth rate, and mood.
Talk with a healthcare provider if you're considering guarana for your child.
Animals: There are reports of poisoning in dogs from herbal products that contain guarana.
Symptoms may include:
Balance problems
Increased temperature
Trouble with walking
Vomiting
Before using guarana in animals, you can contact a veterinarian to talk about the benefits and risks.
Heart conditions: High doses of guarana may be similar to caffeine overdose symptoms, such as abnormal heart rhythm and rate.
Therefore, a healthcare provider may want to monitor you and make any necessary medication adjustments closely.
Liver problems: Guarana has some similar plant substances as green tea. And these substances might have a role in liver toxicity associated with green tea use.
While there are no reports of liver injury with guarana, long-term guarana use at high doses isn't recommended in people with liver problems.
Seizures: Guarana may work against anti-seizure medications and increase your risk of seizures. A healthcare provider may want to monitor you closely and make any necessary medication adjustments if you have seizures.
Dosage: How Much Guarana Should I Use?
Explainer
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
While some studies on guarana in humans exist, more research with high-quality clinical trials is still necessary.
For this reason, there are no guidelines on the appropriate dosage to use of guarana for any condition.
The specific dose may vary based on the dosage form and any medical conditions you may have. If you use guarana, follow a healthcare provider's recommendations or product label instructions.
What Happens If I Use Too Much Guarana?
More information about the safety, toxicity, and overdose of guarana in humans is needed. However, guarana toxicity likely resembles that of a caffeine overdose.
Signs of a potential overdose include:
Heart arrhythmia
Tachycardia
Per a systematic review, side effects might be less of an issue with maximum daily guarana doses of between 500 and 1,000 mg.
But in another review, clinical trials studied daily guarana doses of 3,000 mg.
If you suspect you're experiencing life-threatening side effects, seek immediate medical attention.
Interactions
Guarana might interact with the following medications:
Amiodarone: Amiodarone is a medication for heart arrhythmia. But guarana may reduce amiodarone levels, decreasing amiodarone's effectiveness. For this reason, healthcare providers may recommend against guarana if you take amiodarone.
Anti-seizure medications: Guarana might work against anti-seizure medications. For example, guarana may lower Lamictal (lamotrigine) levels and increase your risk of seizures. Healthcare providers may recommend avoiding guarana if you take lamotrigine for seizures.
It is essential to carefully read a supplement's ingredients list and nutrition facts panel to learn which ingredients and how much of each ingredient is included. Please review the supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.
How to Store Guarana
Storage instructions may vary by product. Carefully read the directions and packaging label on the container.
Generally, medicines and supplements should be stored in a cool, dry place unless otherwise instructed. Keep your medications tightly closed and out of the sight and reach of children and pets, ideally locked in a cabinet or closet.
Discard after one year or as indicated on the packaging. Avoid putting unused and expired products down the drain or in the toilet. Visit the FDA website to learn where and how to discard all unused and expired medications.
You can also find disposal boxes in your area.
Ask a pharmacist or healthcare provider any questions about how to dispose of your medications or natural products.
If you plan to travel with guarana, get familiar with your final destination's regulations. Also, the U.S. Embassy website may be a helpful resource.
Ask a healthcare provider how to travel with your medications or natural products if necessary.
Similar Supplements
Guarana has potential antioxidant effects. Another possible use of guarana is supporting brain health, relieving side effects of cancer or its treatments, and lowering your risk of heart disease.
Other similar supplements may include:
Certain B vitamins: Long-term use of specific B vitamins may slow down worsening memory problems in older adults. These B vitamins may include pyridoxine (vitamin B6), folic acid (vitamin B9), and cyanocobalamin (vitamin B12).
Garlic: Metabolic syndrome is a group of medical conditions that may increase your risk of heart disease. Examples of these conditions include high blood pressure and high cholesterol. Garlic may lower blood pressure, but the evidence is mixed for lowering cholesterol.
Omega-3 fatty acids: Based on available data, omega-3 fatty acids from eating more fish may prevent worsening memory problems in older adults.
Vitamins C or E: Vitamin C and vitamin E are examples of antioxidants. But in the Women's Antioxidant Cardiovascular Study, neither of these vitamins had beneficial effects on heart-related events, such as cardiac arrest and stroke. These vitamins also didn't slow down changes in brain function.
Only combine multiple natural products after talking with a healthcare provider, pharmacist, or dietitian. Checking in can help you avoid possible harmful interactions and side effects and ensure you're giving these supplements a fair trial at appropriate doses.
Frequently Asked Questions
What is the most common dosage form of guarana supplements?
Guarana supplements are available in several different dosage forms—with capsules being the most common.
Are there any guarana products manufactured in the United States?
Yes. Manufacturers in the United States make guarana products.
How do I take guarana safely?
To safely take natural products—like guarana—inform your healthcare providers and pharmacists about any medication changes. This includes over-the-counter (OTC), herbal, natural medicines, and supplements.
Your healthcare provider can help prevent possible interactions and side effects. They can also ensure you’re giving guarana a fair trial at appropriate doses.
Sources of Guarana & What to Look For
There are several sources of guarana, but nutrition guidelines typically favor food sources over supplements.
Although food sources are preferable, there is still a place for supplements for people who have trouble absorbing nutrients, such as people in certain age groups or with certain medical conditions.
Food Sources of Guarana
Guarana is naturally available as a native Amazonian Paullinia cupana (P. cupana) plant from the soapberry family called Sapindaceae.
The U.S. Department of Agriculture (USDA) generally categorizes guarana or P. cupana as food.
Guarana is made by shelling and washing the P. cupana seeds. Afterward, the seeds are dried, roasted, and crushed (grounded) into a powder.
This powder can be used to prepare tea. It's also used as a flavoring agent. In fact, the FDA placed guarana on its approved list of substances added to food.
Guarana is also commonly found in energy drinks.
Guarana Supplements
Guarana supplements are commonly available as capsules.
Other supplement forms include:
Food bars
Gummies or chewables
Liquid
Lozenge
Powder
Tablets
Wafers
Vegetarian and vegan options might also be available. You may also see guarana in combination with other ingredients.
Summary
Guarana is naturally available as a native Amazonian plant from the soapberry family.
It may have potential antioxidant effects, brain health support, heart health support, and relief from the side effects of cancer or its treatments.
But like any medication or natural product, side effects and interactions are possible.
And because no conclusions have been made regarding the efficacy and safety of guarana, it should not be taken in place of getting an accurate diagnosis and treatment for any symptoms or conditions you may have
Before using guarana, involve a registered dietitian, pharmacist, or healthcare provider to help you safely achieve your health goals.
