Fasting blood sugar 8.4mmol/l using metformin treatment, metformin tablets specifications for 0.25g, 0.5g, 0.85g, the general starting dose to eat 0.25g / times; metformin extended-release tablets specifications for 0.5g, the general starting dose to eat 0.5g / times; the number of tablets to take may be 1 tablets, 2 tablets, specifications are different, a few different tablets. The specific dosage needs to be adjusted by the doctor according to the patient’s condition, therapeutic effect, etc., and should be used in accordance with medical advice. The normal value of fasting blood glucose is below 6.1mmol/l, and fasting blood glucose 8.4mmol/l is common in diabetes. Metformin is an oral hypoglycemic drug, which is an effective and safe diabetes treatment drug. Adults taking Metformin tablets usually start at a dose of 0.25g once, two to three times a day, while Metformin extended-release tablets usually start at a dose of 0.5g once, taken once a day. During the medication period, blood glucose, glycosylated hemoglobin, and urine glucose should be tested regularly and the dose should be adjusted by the doctor. Some patients may experience adverse reactions such as nausea, diarrhea, dyspepsia, dizziness, etc. when treated with metformin, once serious and persistent discomfort occurs promptly seek medical attention and be treated by a doctor. People who are allergic to metformin, severe renal failure, severe infections, trauma, hepatic insufficiency, and acute alcoholism should not be treated with this drug. Metformin is a prescription drug, patients should follow the doctor’s instructions to use the drug, do not increase the dose of the drug or stop taking the drug without authorization, in order to avoid serious effects.