The common name of this plant (Paullinia cupana) comes from the Guarani people of northern Brazil who originally used the plant. This tribe, like many others in the area, have been enjoying guard benefits by making a stimulating drink from Guarana seeds for centuries. The fruit of the Guarana vine is bright red, splitting open when ripe to reveal a shiny black seed partially embedded in a white pulp.

From below, these split fruits look like eyes, staring down at those below, which led to several tribal myths regarding this plant. Guarana seeds are very rich in caffeine. The authentic drink/infusion made from the seeds has three to four times the caffeine content of strong coffee.

Traditional Benefits of Guarana

Guarana has always been used, in part, for its powerful and naturally stimulating effects. It was originally used to relieve pain (often from headaches), decrease fever and hypertension, as well as to treat diarrhea. It was commonly brewed as a tea. Since the early 1900s, Guarana extracts have been added to carbonated beverages in South America. In the 1940s, Guarana soda became known as Brazil's national drink. The use of Guarana has spread to both Europe and North America, marketed for its ability to increase mental alertness, decrease fatigue and increase stamina. As such, it is included in many energy and sports drinks.

Stimulating Benefits of Guarana 

Originally, it was believed that a constituent known as guaranine was responsible for Guarana's medicinal properties. We now know that guaranine is nothing more than caffeine. That being said, caffeine does have some well-documented medicinal properties of its own. It stimulates the central nervous system, increases heart rate, raises blood glucose levels and acts as a diuretic and appetite suppressant. Guarana has also been found to contain theophylline and theobromine, other substances similar to caffeine. These effects are also why Guarana can be found in some weight loss supplements. It is also sometimes used to improve physical and mental fatigue in patients undergoing radiation therapies.

Astringent Properties

The seeds also contain tannins, which act as an astringent/have a drying effect and may explain why it can be used to alleviate symptoms of diarrhea. Studies in Brazil have also shown Guarana to inhibit platelet aggregation. There is some preliminary evidence in mice that Guarana also has antioxidant and antibacterial effects. Guarana is a source of catechins and epicatechins, similar compounds to those found in Green Tea.

Supplementing With Guarana & Potential Side Effects

There is no proven effective dose for Guarana, although individuals are advised not to exceed 3 g daily. Stopping Guarana suddenly after daily usage can result in caffeine withdrawal. In general, it is a good idea to follow the manufacturer’s recommended dosage when supplementing Guarana.

Individuals suffering from heart problems, including high blood pressure, kidney disease, hyperthyroidism or any anxiety/nervous disorder should talk to their health care professional before taking guarana, as it may exacerbate these conditions. Do not take guarana while pregnant or breastfeeding. Avoid diet supplements that combine ephedra with guarana, as life-threatening side effects have been reported.