Guarana extract

Guarana extract or guarana seeds or paullinia cupana is a natural stimulant commonly sold over-the-counter. Guarana seeds are also known as Brazilian cocoa or zoom. It is often sold as an "energy supplement" or as in ingredient in "energy drinks" or diet pills.

Caffeine
Guarana contains caffeine, and guarana supplements often contain other active substances, especially additional caffeine.

Side effects
Guarana is considered possibly safe if taken in small amounts, but can trigger an allergic reaction in some people.

It may interact with other herbs, supplements or medication, including those that also affect blood clotting, e.g. garlic/clove, ginkgo, green tea, red clover, Siberian ginseng and turmeric. Some of these are found combined with guarana in herbal supplements or energy drinks.

The most common side effects include:
 * Diarrhea
 * increased heart rate
 * Increased blood pressure
 * Insomnia
 * Nervousness
 * Stomach irrational, nausea, or vomiting
 * Agitation

ME/CFS
Guarana has not be proven to be effective for chronic fatigue syndrome. There are no clinical trials to show its effectiveness or safety in people with CFS.

Learn more

 * Guarana - drugs.com
 * The Use and Abuse of Diet Pills -