Metformin is an oral hypoglycemic drug that is usually taken with or after a meal. Metformin hydrochloride tablets, for example, are usually taken from an initial dose of 0.5 grams twice a day; or 0.85 grams once a day gradually increasing the dose, usually not exceeding the maximum recommended dose of 2,550 milligrams. If in the simple lifestyle intervention blood sugar control does not meet the standard, at this time should should begin to take medication, type 2 diabetes drug treatment is the first choice of metformin. If there are no contraindications to the use of metformin, medication can remain in the treatment regimen. If metformin alone is used for treatment and blood glucose is still not met, then combination therapy may be used. Whether metformin is taken before or after meals needs to be adjusted according to the patient’s tolerance of the drug’s effects. Usually Metformin is recommended to be taken with meals, which helps digestion and absorption of Metformin and better performance of the drug effect. However, some patients may experience nausea and vomiting after taking the drug, which can be recommended after meals to reduce the stimulation of the digestive tract. Whether it is taken after meals or before meals, it will not significantly affect the glucose-lowering effect of metformin. Common adverse reactions of metformin include nausea, abdominal pain, dyspepsia, abnormal taste, etc. Metformin is contraindicated in patients with severe infections, major surgical procedures, and metabolic acidosis. Patients should take metformin under the guidance of a doctor and avoid unauthorized use of the drug.