Hi.

Guarana is a fruit, not herb, originally from the Amazon (Rain, as foreigners call it) Forest. It is mostly consumed in drinks and can be used as an energetic suplement (in powder, capsules, etc.). It has never been listed as a remedy, though, except for extreme tiredness (better than snorting cocaine cause it doesn't damage your health). Guarana has absolutely no effect on sinus/lung congestions and anyone with high blood pressure should stay away from it.

Hope it helps :-)