The main side effects of metformin are gastrointestinal reactions, such as nausea and diarrhea. How to apply it can reduce its side effects? 1, As far as possible, do not take it on an empty stomach or before meals, take it during meals. The absorption of the drug will not be affected, and the adverse reactions will be significantly reduced. Enteric tablets, which can be taken before meals. Just started taking metformin, you can take the drug once at dinner in the first week. 2, adverse reactions are often dose-related, so you should start with a small dose (500 mg/day), and then you can gradually increase the dose to allow the gastrointestinal tract to slowly adapt. The daily dosage should preferably not exceed 2 grams. 3, the use of special dosage forms: such as enteric tablets, slow-release tablets. These dosage forms cause fewer gastrointestinal adverse reactions. Enteric tablets: disintegrate in the small intestine, high bioavailability, reduce gastrointestinal tract irritation, better therapeutic effect when taken half an hour before meals. Extended-release tablets: can be taken once a day to help slow down the gastrointestinal side effects of. If the side effects cannot be effectively reduced, it is no longer appropriate to use this drug, and insulin treatment can be considered.