Guarana is a plant native to South America that is known for its stimulating effects. It is a popular ingredient in energy drinks and is often used as a natural alternative to caffeine. Guarana contains a high amount of caffeine, which can provide a boost of energy and alertness. It is also believed to have other health benefits, such as improving mental focus and reducing fatigue. Guarana can be found in various forms, including tea, supplements, and beverages.