Objective:To investigate the potential antioxidant effects ofPhyllanthus niruri(P. niruri, Euphorbiaceae) tea on healthy subjects.Methods:Five non-smoking, male healthy volunteers, 20 to31 years old, were enrolled.Each subject was treated twice, following a randomized crossover fashion regarding the ingestion ofP. niruri infusion(5 g/750 mL)(tea group) or750 mL of water(control group).Fasting venous blood samples were collected prior to and at1,2 and4 h after infusion drinking.Samples were tested for plasmatic gallic acid and ascorbic acid levels, erythrocytic catalase and superoxide dismutase activities, and intracellularDCFH fluorescence in granulocytes, monocytes and lymphocytes.Results:Catalase and superoxide dismutase activities were not altered by tea ingestion.Plasma levels of gallic acid were significantly increasedat 1,2 and4 h afterP. niruri ingestion and plasma ascorbic acid at1 h afterP. niruri ingestion. Conclusions:Ingestion ofP. niruri tea is associated with a slight increase in antioxidant markers in human blood(ascorbic acid and gallic acid), which may contribute to its pharmacological effects.