4 natural sources of caffeine
Guayusa.
Native to Ecuador's rainforests, guayusa is a caffeinated and antioxidant-rich tea that delivers an earthy flavor. Amazonian people traditionally used guayusa to interpret dreams (really!) and provide clear energy for nighttime hunts; now, as consumers on other continents have discovered guayusa's benefits, it serves as a much-needed income source for South American producers.