Report on Guarana Side Effects and Usage


Natural health supplements sometimes have unexpected side effects or interactions with medication that can lead to adverse reactions that are sometimes life threatening. The following is a list of cautions that you should be aware of before using Guarana (Paullinia Cupana). These are referred to as drug/herb interactions.

Warning 1 – Contraindications: Pregnancy, breast feeding, any history of cardiac problems or high blood pressure. Children should not use guarana.

Warning 2 – Adenosine: Guarana may decrease the adenosine response.

Warning 3 – Antihypertensives: Guarana may decrease the effects of antihypertensives.

Warning 4 – Anxiety: The caffeine in guarana may increase feelings of anxiety.

Warning 5 – Beta-blockers: This herb may increase the effects of beta-blockers.

Warning 6 – Bronchodilators: Guarana may increase the action of bronchodilators.

Warning 7 – Caffeine: Some drugs decrease how quickly your body breaks down the caffeine in guarana. Using guarana with these drugs increases the chance of caffeine side effects including jitteriness, headache, fast heartbeat, and others. These drugs include Cimetidine (Tagamet), Disulfiram (Antabuse), Estrogens, Fluvoxamine (Luvox), and others.

Warning 8 – Diabetes: Some research suggests that guarana may affect the way people with diabetes process sugar (glucose) and may complicate blood sugar control.

Warning 9 – Glaucoma: Guarana increases the pressure inside the eyeball. This increase occurs within 30 minutes and lasts for at least 90 minutes.

Warning 10 – Heart disease: Guarana may cause irregular heartbeat in certain people. Use with caution.

Warning 11 – Hypertension: Using guarana may increase blood pressure in people with high blood pressure. However, this effect might be less in people who use caffeine on a regular basis.

Warning 12 – MAOIs: Using large amounts of guarana while taking MAOIs can result in hypertensive crisis.

Warning 13 – Osteoporosis: The caffeine in guarana can flush calcium out of the body leading to bone loss. This calcium loss might help to weaken bones. To minimize this problem, don’t use more than 300 mg of caffeine per day. Taking calcium supplements may help to offset these calcium losses.

Warning 14 – Postmenopausal women: If you have a genetic problem that affects how vitamin D is used by the body, use this herb with caution.

Warning 15 – Xanthines: When taken with guarana, may increase pulse rate, blood pressure, and arrhythmias.

Warning 16 – Stimulants: Do not combine this herb with stimulants such as amphetamines or ephedrine. Taking guarana along with stimulants can cause too much stimulation and sometimes serious side effects and heart problems.

Warning 17 – Quinolone antibiotics: Some antibiotics decrease how quickly the body breaks down caffeine. Using guarana along with quinolone antibiotics can increase the risk of side effects including jitteriness, increased heart rate, headache, and other side effects. Some of the antibiotics that are of concern include trovafloxacin (Trovan), ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), grepafloxacin (Raxar), and sparfloxacin (Zagam).

Warning 18 – Ephedrine: Guarana should not be taken when formulated with ephedrine in diet aids or performance-enhancing supplements. Potentially fatal irregular heartbeats have been reported to occur.

Used as a natural health remedy: Guarana is used internally for the following benefits and condictions:

  • Aphrodisiac (enhance sexual desire)
  • Antibacterial
  • Antioxidant
  • Astringent
  • Backache
  • Chronic fatigue syndrome (CFS)
  • Diarrhea
  • Enhance athletic performance
  • Fat cell reduction
  • Fever
  • Headache
  • Heart problems
  • Heat stress
  • Improved mood
  • Increased memory retention
  • Increased physical endurance
  • Joint pain (See other herbs for weight loss)
  • Low blood pressure
  • Prevent dysentery
  • Prevent malaria
  • Reduce aggregation
  • Stimulant
  • Weight loss

Side Effects of Guarana

In the USA, guarana has received the designation of “generally recognized as safe” by the FDA. The known side effects of using Guarana at typical doses include:

  1. Delirium
  2. Diuresis (increased secretion of urine)
  3. Increased blood pressure
  4. Increased heart rate
  5. Insomnia
  6. Irregular heartbeat
  7. Nausea
  8. Nervousness
  9. Rapid breathing
  10. Restlessness
  11. Stomach irritation (upset)
  12. Tremors
  13. Vomiting

Although rare, allergic reactions from guarana have been reported. Stop taking guarana and seek emergency medical attention if you experience difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives; or irregular heartbeats or chest pain.

People who use guarana regularly may experience caffeine withdrawal symptoms if they reduce their usual amount. Other side effects may also occur when using Guarana. (See form below)

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