Metformin HCl is a drug to treatment of different diseases such as ovary, diabetes, and slimming. Present study includes the electrochemical analysis by cyclic blood medium at different pH to evaluate the oxidation-reduction current peaks of the metformin compound which appeared at +750 and-750 mV respectively in acidic blood medium, while the oxidation current peak of the metformin was disappeared in alkaline blood medium with present of reduction one, so metformin acts as antioxidant reagent in alkaline blood medium. The study device the patients whom have taken metformin tablets as a treatment for diabetic disease must take ascorbic acid with metformin tablet to avoid the oxidation stress.