Pure guarana powder can be ordered via ebay,
it looks like cacao and has a mildewy aromatic taste.
features large leaves and clusters of flowers,
and is best known for its fruit, which is about the size of a coffee bean.
As a dietary supplement, guarana is an effective energy booster:
As guarana is rich in caffeine, it is of interest for its potential effects on cognition. In rats, guarana increased memory retention and physical endurance when compared with a placebo.
A 2007 human pilot study assessed acute behavioral effects to four doses (37.5 mg, 75 mg, 150 mg and 300 mg) of guarana extract. Memory, alertness and mood were increased by the two lower doses, confirming previous results of cognitive improvement following 75 mg guarana.