Guaraná for Weight Control
Parts Used & Where Grown
Guaraná is an evergreen vine indigenous to the Amazon basin. The vast majority of guaraná is grown in a small area in northern Brazil. Guaraná gum or paste is derived from the seeds and is used in herbal preparations.
How It Works
Caffeine and the closely related alkaloids theobromine and theophylline make up the primary active constituents in guaraná. Caffeine’s effects are well known and include stimulating the central nervous system, increasing metabolic rate, and having a mild diuretic effect.1 One preliminary trial found no significant actions on thinking or mental function in humans taking guaraná.2 Guaraná also contains tannins, which act as astringents and may prevent diarrhea. However, this action has not been studied in human clinical trials.
Why Do Dieters Use It?*
Some dieters say that guaraná helps improve weight loss results.
What Do the Advocates Say?*
The herb guaraná contains caffeine and the closely related alkaloids theobromine and theophylline; these compounds may curb appetite and increase weight loss. Caffeine’s effects are well known and include central nervous system stimulation, increased metabolic rate, and a mild diuretic effect.3 In a double-blind trial, 200 mg per day of caffeine was, however, no more effective than a placebo in promoting weight loss.4 Because of concerns about potential adverse effects, many doctors do not advocate using caffeine or caffeine-like substances to reduce weight.
How Much Is Usually Taken by Dieters?
Guaraná contains substances similar to caffeine that could be responsible for caffeine-like responses in the body, including central nervous system stimulation, increased metabolic rate, and a mild diuretic effect.5 There is no research demonstrating guaraná is effective for weight loss on its own.