Guarana, scientifically known as Paullinia cupana, is a climbing plant of the maple family Sapindaceae. It is native to the Amazon basin, and is commonly found in Venezuela and northern parts of Brazil. Its plant is characterized by large leaves, clusters of flowers and bright red, berry like fruits. The fruits of this plant have small black seeds that contain twice the amount of caffeine found in coffee beans. Guarana extract is being widely used as an energy supplement in various sports and energy drinks in many parts of the world. It is also used in a variety of fat burners and diet pills.

The caffeine content in this plant is much higher than most other plants including coffee beans. But the main point of difference is the slow release time of caffeine. The caffeine from guarana is released at a slower rate, resulting in slower absorption in the body. Hence, it provides a longer and more sustained stimulation than coffee. Despite its various health benefits, this extract is known to have certain adverse reactions on people.

Side Effects
As guarana is chemically identical to coffee beans, its side effects are similar to those associated with caffeine.
  • Nausea
  • Vomiting
  • Insomnia
  • Nervousness
  • Anxiety
  • Restlessness
  • Headache
  • Upset stomach
  • Shakiness
  • Palpitations
  • Shortness of breath
  • Frequent urination
  • Diarrhea
  • Heartburn
  • Hyperactivity
One may not necessarily experience all the above side effects, as they vary from person to person. However, the problems mentioned above are temporary, and may disappear with time.

People with certain health conditions like diabetes, kidney diseases, heart problems, or thyroid problems, may experience serious problems such as:
  • High blood pressure
  • Tachycardia (abnormally rapid heartbeat)
  • Arrhythmia
  • Seizures
  • Chest Pain
  • Difficulty in breathing
  • Tightness in the chest
  • Agitation
  • Stomach cramps
  • Dizziness
These side effects are quite bothersome and need immediate attention of a doctor. Guarana can interact with a number of medications, resulting in serious health hazards. Hence, it is better to stay away from this plant if you have a history of heart or kidney disorders, hypertension, bleeding disorders, osteoporosis, or glaucoma. Some people may also experience signs of allergic reactions after consumption of guarana extract, such as:
  • Hives
  • Rash all over the body
  • Itching
  • Unexplained swelling of the lip, tongue or mouth
  • Difficulty in breathing
  • Difficulty in swallowing
  • Wheezing
Overdose of this supplement can also lead to serious complications, hence, one should avoid its over consumption. However, it is quite difficult to recommend a safe dose of this product, as every person responds differently to caffeine. Some can have several cups of coffee and face no trouble at all, whereas others experience palpitations even after a single cup of coffee. Pregnant women and children are often advised to limit their caffeine intake as it can cause several problems to their health.

An important thing to keep in mind is that this extract has similar properties as of coffee, and hence, one should take the same precautions with it, as one does with coffee.