Metformin Safety: What You Need to Know About Side Effects, Risks, and Real-World Use

When it comes to managing type 2 diabetes in India, metformin, a first-line oral medication used to lower blood sugar by improving insulin sensitivity and reducing liver glucose production. Also known as Glucophage, it's the most prescribed diabetes drug in the country because it’s affordable, effective, and has been used for decades. But safety isn’t just about whether it works—it’s about who it works for, what can go wrong, and how to spot trouble early.

One of the biggest concerns with metformin, a biguanide-class drug that helps control blood sugar without causing weight gain or low blood sugar in most people is its impact on the kidneys, organs that filter waste and help regulate how the body processes metformin. If your kidneys aren’t working well, metformin can build up in your system and lead to a rare but serious condition called lactic acidosis. That’s why doctors check your kidney function before prescribing it—and why you need regular blood tests if you’re on it long-term. It’s not a one-size-fits-all drug. People over 65, those with heart failure, or anyone with chronic kidney disease need extra care.

Most side effects are mild and happen early—stomach upset, diarrhea, bloating, or a metallic taste in the mouth. These usually fade after a few weeks. Taking metformin with food helps a lot. But if you’re getting dizzy, weak, or breathing fast, don’t ignore it. That could be a sign of lactic acidosis, which needs emergency care. Also, avoid heavy drinking while on metformin—it increases the risk of liver and kidney stress. Many people think because it’s cheap and common, it’s harmless. That’s dangerous thinking. Even safe drugs can hurt you if used without understanding your body’s limits.

Metformin isn’t just for diabetes. Some doctors use it for PCOS, prediabetes, or even weight management. But off-label use doesn’t mean it’s risk-free. The same kidney and liver checks apply. And if you’re planning surgery or getting a CT scan with contrast dye, you may need to pause metformin temporarily. Your doctor should tell you this—but if they don’t, ask. You’re the one living with the medication, not them.

Below, you’ll find real-world insights from people who’ve taken metformin, what went wrong, what worked, and what doctors wish patients knew. No fluff. No marketing. Just what matters for your safety.