Q: Dear Dr. Mao,
Is there a difference between guarana and the caffeine in coffee?
A: Guarana, with the latin name Paullinia cupana, is a Brazilian shrubbery that is used in many regional soft drinks as a substitute for caffeine. It is now being used extensively as an additive to energy drinks including Pepsi’s Josta and Mountain Dew MDX, among others.
Unfortunately, it is in many ways similar to caffeine; in fact, it actually contains caffeine—guaranine, theine, and mateina are all official synonyms for caffeine. So, it similarly acts as a CNS (central nervous system) stimulant. Gurana has been involved in some research for weight loss and cognitive function applications but the findings are inconclusive as yet. Furthermore, one of the other constituents of guarana, theophylline, may interact negatively with other medications, including cimetidine and phenytoin.
My take is that it is caffeine from another source. Just like tea or yerba mate, it should be taken in moderation and not be overdone.