aloysia gratissima (gill. et hook) tronc. (verbenaceae) is native to south america with folk therapeutic applications for a wide range of diseases. the polyphenolic and carotenoid profile, toxicity, and antioxidant activity of aqueous extract of aloysia gratissima were investigated. hplc analyses showed high amounts of ferulic acid, trans-cinnamic acid and p-coumaric acid, and also trans-- carotene and lutein which fluctuated throughout the seasons. furthermore, the extract investigated not only exerted antioxidant activity but also inhibited lipid peroxidation. toxicity was achieved only at the highest dose tested. therefore, a. gratissima is a potential species for medicinal purposes.