Metformin Contraindications: Who Should Avoid It and What Alternatives Exist

When you’re managing type 2 diabetes, metformin, the most widely prescribed diabetes medication in the world, used to lower blood sugar by improving insulin sensitivity. Also known as Glucophage, it’s often the first drug doctors recommend because it’s effective, affordable, and doesn’t cause weight gain. But not everyone can take it—and knowing why could save you from serious side effects.

One of the biggest metformin contraindications, conditions where the drug should not be used due to risk of harm is kidney disease. If your kidneys aren’t filtering waste properly, metformin can build up in your body and cause lactic acidosis—a rare but life-threatening condition. Doctors check your eGFR (kidney function number) before prescribing it, and if it’s below 30, they won’t prescribe it at all. Another major red flag is liver disease. Your liver helps clear metformin, and if it’s damaged, your risk of complications goes up. People with heart failure, especially if they’re unstable, are also often told to avoid it. Even heavy alcohol use can increase the risk of lactic acidosis, so if you drink regularly, talk to your doctor before starting metformin.

It’s not just about disease. Some people react badly even with healthy organs. If you’ve had an allergic reaction to metformin before, or if you’re scheduled for surgery or a CT scan with contrast dye, you’ll need to pause it temporarily. Older adults over 80 need extra care, too—kidney function naturally drops with age, and doctors often adjust doses or skip metformin altogether. And while many look for metformin alternatives, other medications or natural approaches that help control blood sugar without the same risks, it’s important to remember: nothing replaces metformin’s proven track record for most people. But when it’s not an option, things like berberine, chromium, or newer drugs like tirzepatide can help. Some people turn to diet and movement alone, and clinics in cities like Bangalore are seeing success with structured, science-backed programs that combine these approaches.

What you’ll find below are real stories and facts about who should avoid metformin, what happens when people take it anyway, and what actually works when the standard treatment isn’t safe. From natural supplements that mimic its effects to medical alternatives that do more than just lower sugar, these posts give you clear, no-fluff guidance—no hype, no guesswork. If you’re wondering if metformin is right for you—or if you’ve been told to stop taking it—this is where you start.