Health Guide


What is it?

Guarana is a caffeine-containing herbal medicine that has been used as a stimulant, aphrodisiac, and appetite suppressant (weight loss).

Other names for guarana include: Paullinia cupana, Brazilian cocoa, Guarana gum, Guarana paste, and Zoom.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breast feeding
  • are taking an asthma medicine called theophylline
  • have chronic headaches, an ulcer, or diabetes
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your doctor, pharmacist, or nurse about how much guarana you should take. The amount depends on the strength of the medicine and the reason you are taking guarana. If you are using this medicine without instructions from your caregiver, follow the directions on the label. Do not take more guarana or take it more often than what is written on the directions.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take guarana without talking to your doctor first if you are taking:

  • Alendronate (Fosamax(R))
  • Medicines to help you sleep, relax, or for seizures (alprazolam (Xanax(R)), lorazepam (Ativan(R)), diazepam (Valium(R)))
  • Cimetidine (Tagamet(R))
  • Clozapine (Clozaril(R))
  • Creatine
  • Dipyridamole (Persantine(R))
  • Disulfiram (Antabuse(R))
  • Fluvoxamine (Luvox(R), Luvox CR(R)) (5)
  • Hormonal contraceptives (birth control)
  • Medicines used for depression or Parkinson's disease (monoamine oxidase inhibitors (MAOIs))
  • Linezolid (Zyvox(R)) (8)
  • Lithium (Eskalilth(R), Eskalith CR(R), Lithane(R), Lithoid(R))
  • Ma huang (Maxadrine(R) with ephedra; Ephedra 1000(R))
  • Methoxsalen (8-MOP(R), Oxsoralen(R), Oxsoralen-Ultra(R), Uvadex(R))
  • Mexiletine (Mexitil(R))
  • Norfloxacin (Noroxin(R))
  • Ofloxacin (Floxin(R))
  • Pantoprazole (Pantoloc(R), Protonix(R))
  • Phenylpropanolamine
  • Riluzole (Rilutek(R))
  • St. John's Wort
  • Terbinafine (Lamisil(R))
  • Theophylline (Elixophyllin(R), Slo-Bid(R), Slo-phyllin(R), Theo-24 (R), Theo-dur(R), Theochron(R), Uniphyl(R))
  • Verapamil (Calan SR(R), Covera-HS(R), Isoptin(R), Verelan(R), Verelan PM(R))


  • Before taking guarana, tell your doctor if you are pregnant or breast feeding
  • Taking large amounts of guarana or taking it for too long may cause anxiety, diarrhea, headache, irritability, nausea (upset stomach), vomiting (throwing up), heart problems, and seizures (convulsions) (1)
  • Do not use guarana for a long period of time (2)
  • Do not take guarana if you have chronic headaches, an ulcer, or diabetes (1)
  • Do not drink alcohol when using guarana
  • Do not take guarana if you are taking an asthma medicine called theophylline

Side Effects:

Stop taking your medicine right away and talk to your doctor if you have any of the following side effects.

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing, or rash.

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Guarana has caffeine-like effects that may include causing you to need to pass urine more often, feel nervous or irritable, or to have insomnia (cannot sleep) (1).
  • Taking large amounts of guarana or taking it for too long may lead to anxiety, diarrhea, headache, irritability, nausea (upset stomach), vomiting (throwing up), heart problems, and seizures (convulsions) (1).
  • Feel dizzy, weak, or tingling in your face, arms, or legs (8)


1. Fetrow CW & Avila JR: Professional's Handbook of Complementary and Alternative Medicines. Springhouse Corporation, Springhouse, PA; 1999.

2. McGuffin M, Hobbs C, Upton R et al: A Botanical Safety Handbook. CRC Press, Boca Raton, FL; 1997.

3. Carrillo JA & Benitez J: CYP1A2 activity, gender and smoking as variable influencing the toxicity of caffeine. Br J Clin Pharmacol 1996; 41:605-608.

4. Pakes GE: Phenelzine-cola headache. Am J Hosp Pharm 1979; 36:736.

5. Jeppesen U, Loft S, Poulsen HE et al: Fluvoxamine-caffeine interaction study. Pharmacogenetics 1996; 6:213-222.

6. Kuribara H & Tadokoro S: Caffeine does not effectively ameliorate, but rather may worsen the ethanol intoxication when assessed by discrete avoidance in mice. Japan J Pharmacol 1992; 59(3):393-398.

7. Haller CA & Benowitz NL: Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000; 343(25); 1833-1838.

8. Product Information: Zyvox(R) IV injection, oral tablets, oral suspension, linezolid IV injection, oral tablets, oral suspension. Pharmacia & Upjohn Company, New York, NY, 2008.

Last Updated: 7/4/2018
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