Guarana Extract (Paullinia Cupana) Uses, Benefits, Dosages & Side Effects

Guarana extract is an energy-boosting dietary supplement commonly used to promote athletic performance, stamina and motivation.

Guarana seed contains high amounts of caffeine, typically between 2.0-7.5% by weight. This makes it a more concentrated source of caffeine compared to coffee beans, which contain 1-2% by weight. [6]

Extracts from the seeds of this plant are typically used for increasing physical energy, mental alertness and for weight loss. They are also taken by bodybuilders as part of pre-workout supplement stacks.

Guarana is a common ingredient in many energy drinks, protein bars, and weight loss supplements. [6] Red Bull, Monster and Rockstar energy all contain this herbal extract.

In addition to its stimulant effects, guarana is also used to enhance cognitive function, increase libido, as a diuretic, to improve mood balance and reduce the effects of stress and fatigue.

This article will review what guarana is, how it works, purported health benefits, typical dosages and possible side effects.

Guarana

Herbal Supplement

Energy

Alertness

Focus

How It Works:

• Highly concentrated source of caffeine
• Enhances energy levels and alertness
• Exhibits mood-boosting & nootropic effects

Dosage:

Between 200-1600 mg per day

Safety:

Rated Possibly Safe

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What is Guarana

Guarana (Paullinia cupana) is a creeping shrub that clings to trees, growing to heights more than 36 feet. It is native to the Brazilian Amazon; particularly the Parintins and Manaus regions. [3]

These plants develop small, round, red/brown fruits that contain black seeds. The seeds are surrounded in white arils.

Guarana seeds are typically roasted and ground into powder for use in traditional beverage and food making. [3] This herb has also been used traditionally as a medicine, most commonly as a stimulant.

Examine states that guarana contains several xanthine compounds such as caffeine. The seeds also contain phenolic compounds such as tannins, catechins, and procyanidins. [1]

These active chemicals have been studied individually and their effects are well understood. However, there is limited research into their synergistic effects. More research is still needed to determine exact mechanisms of action. [1]

The Raintree Tropical Plant Database (RTPD) states that the xanthines in guarana are alkaloids including caffeine, theobromine, and theophylline. [3]

In human studies, theophylline has been shown to stimulate the heart muscle and Central Nervous System (CNS), and to decrease fatigue and increase mental alertness. [3]

RTPD states that guarana also contains various other phytonutrients of interest to researchers including:

• Protein
• Resin
• Glucose
• Starch
• Catechins
• Tannins
• Sucrose
• Salicylic Acid
• Nicotinic Acid
• Mucilage [3]

Depending on the source, guarana is said to contain between 2-10 times the caffeine generally contained in coffee beans. [1, 2, 6][7]

Most of the proposed health benefits of consuming this plant are attributed to its caffeine content.

Some of the known mechanisms of caffeine include stimulating the CNS, slowing down blood platelet aggregation, elevating blood glucose levels, facilitating fat loss, increasing cardiac activity, raising blood pressure, increasing urine production, and stimulating skeletal muscles. [7]

The Memorial Sloan Kettering Cancer Center (MSKCC) states that in in vitro (cultured cell) and animal studies, guarana was shown to have an antioxidant effect and inhibited the peroxidation of lipid molecules.

Long-term exposure to the seed extract also has an anxiolytic (anti-anxiety) effect which was mediated by the dopamine and serotonin neurotransmitter systems. [7]

MSKCC states that theophylline in guarana extract also dilates bronchial tubes and help to improve asthma symptoms. Theobromine has similar effects to theophylline. [7]

Traditional Medicine Uses

Jesuit missionaries in the Amazon noticed that native tribesmen consumed guarana seeds to give them energy while on long hunting trips or when fasting for extended periods.

The missionaries brought the seeds back to their home countries and this product has been gaining worldwide popularity since then. [4]

Traditional uses for the seeds included increasing libido as an aphrodisiac, improving tolerance to dietary restrictions, and protecting against dysentery and malaria. [5]

Caffeine was identified in guarana in 1840. From 1880-1910, it was listed in the US Pharmacopeia. [5]

In Brazil, drinks containing guarana are consumed more than any other beverage except Coca-Cola. Like other caffeine-containing drinks, some people mix it with alcohol to intensify the intoxicating effects. [5]

This ingredient is found in more than 100 beverages around the world, most commonly soft drinks and energy drinks. Some popular brand names include Mountain Dew MDX, AMP, Monster, Jolt, and Rip It energy drinks. [2]

The Natural Medicines Comprehensive Database (NMCD) states that guarana supplements are used orally (by mouth) for:

• Chronic fatigue syndrome (CFS)
• Enhancing athletic performance
• Enhancing cognitive function
• Hypotension (low blood pressure)
• Increasing appetite
• Menstrual cramps
• Reducing mental and physical fatigue
• Weight loss [6]

The NMCD reports that guarana is also used as an aphrodisiac (increases sex drive), astringent (contracts skin and other body tissues), diuretic (increases urine volume), tonic (increases well-being), and a central nervous system (CNS) stimulant. [6]

It is also used in traditional medicine practices for dysentery (intestinal infection), malaria (fever from parasitic infection), and chronic diarrhea.

It has been used for heart problems, fever, rheumatism (joint/muscle/fibrous tissue swelling/pain), lumbago (lower back bone/muscle pain), heat stress and headache. [6]

Guarana Health Benefits

The purported health benefits of guarana are based in traditional medicine practices. It is also used as a natural source or caffeine.

At this time, human research into the effects of this plant extract are limited. While the active constituents found in this plant are well-researched, guarana extract itself has not been studied extensively.

There have been some promising results from clinical research studies using this supplement for anxiety, chemotherapy-related fatigue, cognitive performance, exercise tolerance, and obesity/weight loss.

These studies are limited in number and more research is needed to determine the therapeutic efficacy of guarana for these and other uses.

Cognitive Performance

Guarana is commonly taken to enhance cognitive performance, memory, and reaction time. It is frequently added to nootropic stacks as a source of caffeine.

Clinical research has found benefits, but there have been some conflicting results seen in other trials.

Preliminary clinical evidence from one study suggests that, in healthy people, 75 mg guarana can increase cognitive task performance speed, compared to placebo, for as long as 6 hours. In that study, the extract used contained 11-12% caffeine. [6]

In another study, 500 mg guarana powder (2.1-2.5% caffeine) did not improve cognitive function, relative to a placebo in middle-aged or elderly adults. [6]

Guarana has also been studied for its effects on brain performance in conjunction with other ingredients such as vitamin B, vitamin C, and various minerals.

In one study, it was found to decrease mental fatigue and increase visual information speed and accuracy. [6]

In another study, a combination supplement with gaurana improved working memory and attention compared to both a placebo and a control that contained just the vitamins and minerals. [6]

Dr. Joseph Mercola says that this supplement contains several stimulants, including caffeine, that work together to keep you more alert for hours.

According to Dr. Mercola, “guarana slowly releases the caffeine into your system, allowing you to feel the effects over a longer period of time compared to coffee.” [4]

These clinical trials are limited, and more research is needed to determine if and how guarana can support cognitive function.

Weight Loss and Obesity

Guarana may support weight loss and make it easier to maintain a healthy weight. This plant contains the stimulant caffeine which increases metabolic activity.

Some clinical research on the effects of guarana for weight loss in overweight patients has shown positive results.

According to Dr. Mercola, “Since caffeine is considered to be a stimulant, your alertness and physical performance improve. This requires more energy to burn, and guarana works by mobilizing the stored fats and glucose in your body and using them as fuel, which in turn, can help you lose weight.” [4]

Dr. Mercola also says that this supplement may promote muscle recovery after physical exertion. It may work by preventing lactic acid accumulations that contribute to muscle soreness. [4]

The NMCD states that guarana, taken along with damiana and yerba mate, has been observed in clinical research to cause some weight loss in overweight patients compared to a placebo. [6]

Some other preliminary evidence suggests that a specific product, called Metabolife-356, might help with weight loss efforts. When used along with a healthy diet and daily exercise, this product helped to facilitate a 5.95-pound weight reduction over an 8-week period. [6]

However, Metabolife-356 contains various other ingredients besides guarana including ephedra and 17 additional vitamins, minerals and nutrients. [6]

It is not known how effective guarana is on its own for obesity and weight loss. To promote long-term weight management, it is important to adopt a healthy diet and exercise regimen as well.

Anxiety and Mood Balance

Guarana has long been used to promote mental well-being, improve resistance to emotional stress and alleviate tiredness.

The NMCD reports that a specific guarana-containing product reduced the severity of anxiety in some patients with adjustment disorder with anxious mood. [6]

The product studied in this clinical trial is Euphytose. It contains various other ingredients as well including valerian, hawthorn, kola nut, black horehound and passionflower.

Taking two tablets three times daily for 28 days was shown to reduce anxiety. However, it cannot be said that guarana alone would have the same effects. [6]

More research is required in order to determine whether this supplement works on its own to reduce feelings of anxiety.

Guarana Supplements

Guarana supplements are available in capsules, powders, seeds, liquid extracts, tinctures, drinks, and sticks made from dried seed paste.

Currently, the Natural Medicines Comprehensive Database reports that there are over 1700 different products available that are labelled to contain this ingredient. [6]

It is important to research dietary supplements and their manufacturers before purchasing any specific brand. Look for organic, non-GMO products sold by cGMP-compliant manufacturers that perform third-party lab testing.

Guarana supplements are typically sold in serving sizes between 800-1000 mg per tablet/capsule. Most manufacturers recommend taking one or two tablets per day, for a total dosage of up to 2000 mg per day.

The authenticity of supplement ingredients is an on-going issue. Sometimes products that claim to contain this extract contain a lower amount of the ingredient then advertised.

Some low-quality products may not contain guarana at all but rather caffeine from another source.

The RTPD reports that the US FDA tested 24 different commercially-available guarana products. Of those, 14 were found to contain less of this compound than claimed or no guarana extract at all. [3]

According to the RTPD, “Manufacturers buying guaraná extracts and standardized extracts should demand assays that show not only the caffeine content – but the theobromine and theophylline content as well. This will determine if the actual seed was concentrated into an extract.” [3]

It is recommended to do your research thoroughly on any supplements you are considering. Contact manufacturers and ask for Certificates of Analysis (COA) to help confirm the supplements contain guarana.

Recommended Dosage Guidelines

According to Examine, the standard dosage for guarana extract is 50 – 75mg once per day. It should be taken early in the morning to avoid disruptions to the sleep cycle.

Divided dosages have also been used up to 50 mg twice per day, for a total dosage of 100 mg per day. These dosages are typically taken shortly after waking up in the morning and shortly after lunchtime. [1]

These dosages are based on the caffeine content of the guarana extract. Different extracts will be standardized to different concentrations of caffeine.

The RTPD reports the following general dosage guidelines for guarana:

• 1-2 grams capsules, 2-3 times each day
• 1 cup decoction, 1-3 times each day
• 1-3 ml tincture, 2-3 times each day [3]

In research trials on cognitive performance and exercise tolerance, a specific product (Berocca Boost) containing 222.2 mg per day has been used. In a trial on obesity, 855 mg per day was used. [6]

Most supplements provide between 800-1000 mg extract per tablet, and between 1-2 tablets per day is recommended. Taking a lower dosage is acceptable, but higher dosages are typically not recommended without a doctor’s input.

As with most supplements, the optimal serving size will depend on a variety of factors including purpose of use, personal physiology, age, sex, and tolerance.

It is best to discuss the appropriate way to take this supplement with a doctor who understands your health history.

Guarana Side Effects

The Natural Medicines Comprehensive Database rates guarana as Likely Safe when consumed in amounts found in food. It is rated Possibly Safe when used orally and appropriately at medicinal amounts, short-term. [6]

The NMCD has rated this compound as Possibly Unsafe when used orally in high dosages long-term. It is rated Likely Unsafe when used orally or injected in very high dosages.

These safety ratings are based on the high caffeine content and its known negative effects at excessive doses.

The NMCD reports that guarana is generally well-tolerated in healthy individuals. Most information concerning possible adverse effects is based on the negative effects of caffeine. [6]

Caffeine can cause insomnia, restlessness, nausea, vomiting, elevated heart rate, nervousness, and increased breathing. These effects are typically only experienced at moderate to high dosages, but it can produce adverse reactions in some people even at low doses. [6]

The adverse side effects associated with caffeine are generally more intense in children and elderly people. [6]

Large amounts of caffeine may cause habituation, tolerance, and psychological dependence. Suddenly discontinuing chronic use of caffeine can cause withdrawal symptoms like irritability, headache, dizziness, anxiety and nervousness. [6]

Guarana should be taken in the mornings because of its stimulant properties. Using it late in the day can cause sleeping disturbances. [1]

Drug and Supplement Interactions

Guarana may interact with a number of drugs, herbs, laboratory tests, and health conditions. These interactions are attributed to its caffeine content.

Be cautious mixing this herbal extract with alcohol as this substance slows down caffeine metabolism. This combination might increase the effects and side effects of the caffeine content in guarana. [6]

Guarana might inhibit blood platelet aggregation and increase the risk of bruising or bleeding.

Be careful using supplements along with antiplatelet/anticoagulant drugs including aspirin, clopidogrel (Plavix), dipyridamole (Persantine), ticlopidine (Ticlid), heparin, and warfarin (Coumadin). [6]

Using this supplement along with oral contraceptives might amplify its physiological effects. Oral contraceptive drugs are known to reduce caffeine clearance in humans by 40-65%. [6]

Quinolone antibiotics like ciprofloxacin (Cipro), gatifloxacin (Tequin), levofloxacin (Levaquin), moxifloxacin (Avelox), norfloxacin (Noroxin), and sparfloxacin (Zagam) decrease caffeine clearance.

Use caution if combining guarana with:

• Caffeine-containing herbs and supplements, like bitter orange and black oolong tea
• Calcium
• Creatine
• Ephedra (ma huang)
• Herbs and supplements with anticoagulant/antiplatelet properties like garlic and ginger
• Magnesium [6]

Guarana might affect results of lab tests that measure 5-hydroxyindoleacetic acid, bleeding times, glucose, creatine, catecholamines, lactate, pharmacological stress, pulmonary function, or neuroblastoma diagnosis markers.

This supplement might also affect results on lab tests that measure urate, theophylline, urinary calcium, or vanillylmandelic acid.

Use of this product might exacerbate symptoms of some health conditions including anxiety disorders, bleeding disorders, diabetes, cardiac conditions, and hypertension (high blood pressure). It may also affect glaucoma, IBS (irritable bowel syndrome), and osteoporosis.

You should discontinue using this supplement at least two weeks before any scheduled surgeries.

Guarana may interact with other drugs, herbs and supplements. Check with your doctor before taking this supplement to determine if it is appropriate for you.

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