Guarana contains a compound called Guaranine which is almost identical to caffeine. The effects of Guaranine will thus closely mimic the effects of caffeine. Guarana stimulates the central nervous system, increases the metabolic rate and has a mild diuretic effect. Guarana also contains tannins which act as astringents and help to prevent diarrhoea. Guarana is used to enhance athletes to perform better, for fatigue and those with hectic lifestyles, and is also used for weight loss and obesity.
