Guarana is commonly used for weight management, to enhance athletic performance, as a stimulant, and to reduce mental and physical fatigue, and is a frequent addition to energy and weight loss products.

Guarana is a plant named for the Guarani tribe in the Amazon, who used the seeds to brew a drink. Guarana contains caffeine that works by stimulating the central nervous system (CNS), heart, and muscles. Guarana also contains theophylline and theobromine, which are chemicals similar to caffeine.