The antihyperglycemic activity of crude extract of Moringa oleifera leaves and the isolation of phenolic compounds with antioxidant activity by bioassay on leaves grown in Brazil were used for the first time. Our results show that three phenolic compounds with high antioxidant activity were isolated and that the chemical composition of the crude extract of EO rich in flavonoids may be closely related to the antihyperglycemic effect. Antihyperglycemic activity of crude extract and isolation of phenolic compounds with antioxidant activity from Moringa oleifera Lam. Antihyperglycemic activity of the crude extract and isolation of phenolic compounds with antioxidant activity from Moringa oleifera Lamb. Thus, it is possible that these compounds can be used as chemical biomarkers of this plant in Brazil to ensure the quality and support the use of the above-ground parts in traditional medicine. In providing the information contained herein, we do not diagnose, treat, cure, alleviate, or prevent disease or illness of any type. It is recommended that you seek the advice of a qualified health care professional before beginning any natural, integrative, or conventional treatment.