For the extended-release form of metformin, one capsule a day can lower blood glucose. However, in the case of the regular (non-extended-release) form of metformin, taking only one capsule a day is generally not sufficient to achieve a sustained normalization of blood glucose, and is not recommended, so please follow your doctor’s instructions. Metformin is a commonly used hypoglycemic agent. Metformin can effectively improve the uptake of glucose by peripheral tissues in diabetic patients, reduce insulin resistance, improve insulin sensitivity, and thus promote the decline of blood glucose. Metformin in regular dosage form is a short-acting drug with a half-life of only about 1.5~1.8 hours, so in order to maintain diabetic patients’ blood glucose normal throughout the day, Metformin in regular dosage form is usually taken 2-3 times a day, 1 capsule/tablet (0.25g/0.5g) at a time, and the dose is gradually adjusted according to the efficacy in the future. The extended-release dosage form of metformin, on the other hand, can be taken once a day, usually 1 capsule/tablet (0.5g) at a time, with dinner, and the dosage is adjusted according to blood glucose. To summarize, whether taking one tablet of metformin a day can effectively lower blood sugar is related to the dosage form of the drug taken, the specific choice of hypoglycemic drugs, the amount of medication and the number of times to take medication, etc., need to be evaluated by a professional physician to give guidance, please follow the doctor’s instructions.