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What should I know about metformin side effects?

Answered by the AskDoc Medical Team · Medically reviewed under our Medical Director, MBBS

Metformin's common side effects live in the gut: loose stools, cramps and nausea, mostly in the first weeks. Taking it with food and building the dose slowly tames it for most people, and extended-release versions are gentler still.

Long-term use can lower vitamin B12, worth checking every year or two, especially with tingling or anemia.

Despite the reputation, metformin remains one of the best-studied, safest diabetes medicines. Never stop it on your own; if the gut effects will not settle, that is a dose-and-formulation conversation with your prescriber.

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