People with diabetes can usually take metformin, which is often used as the drug of choice for people with type 2 diabetes, but it needs to be used under the supervision of a doctor and not by choice. Metformin is the first-line medication for people with type 2 diabetes. Metformin can increase insulin sensitivity, promote the use of glucose in peripheral tissues, inhibit the role of hepatic glycogen output, which can better control blood sugar. Although metformin has its own hypoglycemic advantages, it also has adverse effects, including diarrhea, cachexia, vomiting, bloating, fatigue, myalgia, rash, and dizziness. It is contraindicated in patients with severe renal insufficiency, decompensated heart failure, severe infections, major surgical operations, and acidosis. Therefore, it is recommended that diabetic patients use the medicine reasonably under the guidance of professional physicians.