Metformin: How to Reduce Diarrhea and Stomach Upset
Diarrhea, nausea, and abdominal discomfort are known metformin effects, especially after starting or increasing a dose. Do not stop or change it without guidance.
Take it exactly as prescribed
Immediate-release metformin is commonly taken with meals, while extended-release is often taken with the evening meal, depending on the prescription. Food may improve tolerance. Do not split, chew, or crush an extended-release tablet.
What to discuss if symptoms continue
A clinician may consider slower dose increases, a different schedule, or an extended-release formulation. Record dose, time, food, and symptoms. There is no single solution, and persistent diarrhea may have another cause.
Hydration, kidneys, and procedures
Severe vomiting or diarrhea can dehydrate you. Kidney disease, contrast imaging, surgery, or acute illness may require specific temporary instructions. Call your care team rather than deciding alone when to stop or restart.
Warning signs
Seek prompt care for extreme weakness, rapid or difficult breathing, unusual drowsiness, persistent vomiting, severe abdominal pain, major dizziness, or feeling very cold. Lactic acidosis is rare but serious; MedlinePlus lists these warning signs.
Frequently asked questions
Can I take it without food?
Follow your prescription; it is commonly taken with meals to reduce stomach upset.
Does extended-release cause less diarrhea?
Some people tolerate it better, but a clinician should make the change.