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What Are the Most Common Guarana Side Effects?

Heather Martin
Heather Martin

The most common guarana side effects typically include increased heart rate, jitters, insomnia and nausea — usually the same effects one would feel after consuming high doses of caffeine. Gurana berries, from which most dietary supplements are made, contain a lot of caffeine. As such, other caffeine side effects such as hyperactivity and increased urination are common, too. People who take excessive amounts of the supplement may also experience nervousness, paranoia, and even convulsions in serious cases. It’s generally thought that extracts and powders made from the guarana plant are much more effective as stimulants than supplements and brews made from coffee and tea plants, but they also carry more risks. It is easier to overdose on the supplement, too, which has been linked to death in rare cases. People who are interested in adding guarana to their diets or vitamin supplementation plans are usually wise to talk about proper dosing with a qualified healthcare provider before beginning, and should usually get medical help if side effects get worse or don’t seem to go away on their own.

Understanding the Supplement Generally

Guarana is a tropical berry that can be used to make a dietary supplement of the same name. The plant is known scientifically as Paullinia cupana

An allergic reaction to guarana may include the development of hives.
An allergic reaction to guarana may include the development of hives.

, and its berries, which turn bright red when ripe, are where most of the nutrients and stimulant potential are held. The plant is a type of climbing vine that grows most prolifically in the Amazon river region of Brazil, but can be found throughout much of Central and South America. The berries have been used by local communities for cooking and brewing for centuries, but have found their way into the Western health and supplement market in recent years thanks in large part to their very high concentrations of caffeine.

One possible side effect of guarana is heart palpitations.
One possible side effect of guarana is heart palpitations.

The berries are most commonly used as a stimulant and appetite suppressant. The pods contain approximately 250 percent more caffeine than coffee, so users are advised to moderate their intake to avoid guarana side effects. Consumption of other products containing caffeine, such as coffee, tea and chocolate, should also usually be limited while taking guarana, since guarana and caffeine from these sources are released into the blood stream at similar rates. In many weight loss and energy supplements, the supplement is often used in conjunction with caffeine or ephedra. Taking ephedra and guarana together may also increase the risk of side effects, so users should be cautious in these situations.

Increased Heart Rate and Jitters

Guarana is a dietary supplement made from tropical guarana berries.
Guarana is a dietary supplement made from tropical guarana berries.

One of the first things people unaccustomed to caffeine might experience while taking guarana is a feeling of restlessness, often accompanied by trembling and a general feeling of jitteriness. In high doses the stimulate can also increase heart rate, which can make people feel their heart pounding, as if in the midst of intense exercise despite sitting still. Most of these effects are short-lived, and regular consumption typically leads to at least a certain degree of tolerance. Just the same, regular consumption of very high quantities can lead to health problems down the line.

The supplement is also commonly linked to hyperactivity and trouble sleeping. In the daytime hours alertness is often desired, and may even be why people take the supplement. Near bedtime, though, this effect is often problematic.

Nausea and Heartburn

People might also feel nauseated, particularly if the supplement is taken on a relatively empty stomach. Guarana is often used as a white powder added to drinks, but it also is present in pill form. Experts usually recommend taking it with food to prevent stomach upset and heartburn, also known as acid reflux, which is another potential side effect.

Dosing Precautions

The supplement isn’t usually recommended for individuals who have certain health conditions. Guarana contains very high amounts of caffeine, so pregnant and nursing women should not take guarana without first consulting a doctor. People with cardiac problems or high blood pressure, kidney disease, hyperthyroidism, or any of a range of anxiety disorders also should contact their doctor before taking the stimulant, since for these people the side effects can be even more pronounced than normal.

In most places this and other dietary supplements aren’t regulated for health benefits, potency, purity or safety, so there might be risks or even advantages that are unknown. Among other things, the lack of regulation means that the amount of guarana in supplements could be greater or less than the amount reported on the label. Supplements also could be contaminated with toxic metals or other drugs. To reduce these concerns, dietary supplements should only be purchased from a trusted source and taken sparingly at first.

Special Considerations for Athletes

Some athletes believe that caffeine helps them perform better physically and mentally in sports that require endurance. Guarana use in sports competitions is not typically restricted by sporting authorities. This drug is a caffeine source, however, so users must limit their caffeine use to the level that is accepted during competition. Athletes should keep in mind that caffeine's effects vary depending on the person, his or her metabolism, the amount of intake, and the frequency of intake.

Symptoms Associated with Withdrawal

Caffeine withdrawal causes side effects such as headache, irritability, nausea, depression, constipation, muscle stiffness and flu-like symptoms. Those trying to break their caffeine habit should cut down their intake gradually in order to reduce withdrawal symptoms.

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Discussion Comments


@stoneMason-- I agree with you. I've had guarana sodas and energy drinks before as well. But last week I tried a different guarana product, a powder that I mixed into orange juice as an energy drink. I got a very bad headache after ten minutes. A few days later, I tried it again thinking that the headache was unrelated but I got the headache again and this time, in addition to nausea.

So all guarana products are not good quality and some of them contain way too much guarana extract.


I think that guarana is a fairly safe fruit but it can cause side effects if the dosage is very high or if the product is poor quality. I grew up drinking guarana soda and never had any problems.


This supplement should not be used by people who have high blood pressure or other cardiac problems and people who have anxiety.

I have high blood pressure and tried a very low dose of guarana extract for the energy benefits. Soon afterward, I felt unwell and checked my blood pressure and it was fairly high. This is abnormal for me since I take blood pressure medications. I also had heart palpitations and anxiety.

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    • An allergic reaction to guarana may include the development of hives.
      By: Jürgen Fälchle
      An allergic reaction to guarana may include the development of hives.
    • One possible side effect of guarana is heart palpitations.
      By: forestpath
      One possible side effect of guarana is heart palpitations.
    • Guarana is a dietary supplement made from tropical guarana berries.
      Guarana is a dietary supplement made from tropical guarana berries.