---
title: "Metformin side effects long-term: risks and signs"
description: "Metformin side effects long-term are usually manageable, but B12 deficiency and rare lactic acidosis matter. Know symptoms and when to call a clinician."
canonical: "https://www.vitalsvault.com/treatment-learn/metformin-side-effects-long-term"
last-updated: 2026-08-22
---

# Metformin side effects long-term: risks and signs

> Metformin side effects long-term are usually manageable, but B12 deficiency and rare lactic acidosis matter. Know symptoms and when to call a clinician.

---

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