Guide to Guarana Weight Loss Pills

Reviewed by Terri Forehand RN

Many people sing the praises of the guarana weight loss pill. However, before you take any non-prescription or prescription diet pills, it's important to learn about the drug's effects, both potentially good and bad.

General Information

Guarana, also referred to as paullinia cupana, is actually looked upon as a source for a health drink in countries like Brazil, where it is a popular soda. It's only in the last few years that it has gained popularity and notoriety in the United States.

  • It comes from a creeping shrub typically found in the Amazon rain forest of Brazil and in Venezuela.
  • According to WebMD, its seeds contain as much as four to six percent caffeine. Coffee beans typically only contain one to two percent caffeine.

Weight Loss Supplements

Many weight loss supplements contain guarana alone or in combination with other herbal ingredients. Some studies have hinted that guarana may be effective.

  • A 2011 study found habitual guarana intake appeared to provide some protection against metabolic disorders in older adults.
  • A 2001 study showed that supplements containing guarana and Ma Huang promoted short term weight and fat loss. Ma Huang contains ephedra.

Guarana may also be helpful in weight loss because its caffeine content contributes to a temporary rise in energy levels, which may help you have the energy to work out regularly as part of your weight loss routine.

Health Concerns

Because of its high caffeine levels, guarana is used as a stimulant and appetite suppressant.

Side Effects

As with any stimulant and weight loss pills, dangerous side effects are possible. Because the FDA (Federal Drug Administration) has not weighed in on the effects and safety of using guarana weight loss pills, users must proceed at their own risk. WebMD notes side effects are more likely to occur at higher doses. These side effects may include:

  • Potentially fatal, irregular heartbeats
  • Insomnia
  • Nervousness
  • Increased heart rate
  • Increased blood pressure
  • Increased respiration
  • Tremors
  • Delirium
  • More frequent urination
  • Dehydration
  • Ringing in the ears
  • Headaches
  • Stomach pain
  • Caffeine withdrawal when attempting to quit
  • Painful urination

These side effects may be dose dependent.


WebMD also notes certain people shouldn't take guarana. If you have any of the following conditions, talk with your doctor before using guarana, because dangerous side effects and complications may exist.

  • Pregnancy or lactation
  • Low tolerance level to caffeine
  • Heart conditions
  • Diabetes
  • High blood pressure
  • Kidney disease
  • Epilepsy
  • Overactive thyroid
  • Insomnia
  • Anxiety disorders
  • Bleeding disorders
  • Diarrhea

Drug Interactions

According to HealthLine, guarana may have dangerous interactions with an array of medications and supplements. Most of these interactions are the result of guarana's caffeine content.

  • Amphetamine
  • Drugs that thin blood such as aspirin, heparin, NSAIDs, anti-platelet medications, and warfarin
  • Diabetes medications such as insulin
  • Benzodiazepines such as alprazolam (Xanax) or lorazepam (Ativan)
  • Sedatives
  • Cimetidine (Tagamet)
  • Antibiotics such as ciprofloxicin
  • Anti-psychotic medications such as clozapine
  • Other central-nervous system stimulants
  • Hormonal birth control pills

HealthLine also notes if you are taking any type of ephedra product, you should avoid guarana as well. Combining this supplement with ephedra or other stimulants could result in an increased risk of stroke, heart attack, increase in blood pressure, hemorrhages, and other problems.

Using Guarana Safely

If you do decide to use guarana, safety is of the utmost importance.

  • Talk with your doctor before taking any weight loss pill, supplement, or herb designed to burn fat and/or encourage weight loss.
  • Purchase this supplement from a reputable health food store or pharmacy.
  • Don't buy over the Internet unless you know the company you are dealing with is trustworthy. Remember, if you buy from an unknown company online, you may not be getting what you believe you purchased.
  • Use the drug only as directed or as your doctor recommends. Doubling up on doses could cause serious health risks.
  • Read the ingredients on the package to see what else the pills may contain.
  • Do not give this or any other diet pill or supplement to a child. Large amounts of caffeine can cause serious health problems in children.

Risks Versus Benefits

There are no miracle diet pills. Even those containing ingredients such as guarana have limitations and risks. It's important that you talk to your doctor about your weight loss goals before taking supplements that contain guarana. Your physician can help you determine if the benefits of such supplementation outweigh the potential health risks.

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Guide to Guarana Weight Loss Pills