Metformin: Misunderstood but life-saving

Metformin is one of the most prescribed medications for type 2 diabetes — and for good reason. It is effective, affordable and well-studied. It also plays an important role in preventing diabetes in persons with prediabetes. Yet despite all these benefits, Metformin remains surrounded by myths and misinformation, especially on social media.

We have had patients tell us, “Doc, I heard it’s bad for your kidneys,” or “Is it true doctors don’t use metformin anymore?” These fears are often stoked by viral posts or articles that look convincing but are riddled with inaccuracies.

One widely shared piece even claimed that metformin is no longer being prescribed. That’s simply not true. We continue to prescribe it regularly to patients because it works — and it saves lives.

Many of these online articles are written with a hidden agenda. They start by tearing down a trusted medication like Metformin and end with a sales pitch for a so-called “miracle cure,” usually an expensive supplement with no scientific basis. Please be cautious. Never buy medications or supplements from social media platforms. Always talk to your doctor.

Now back to the most common concern we hear: “Doc, di ba nakakasira ’yan ng kidney?”

No, metformin does not cause kidney damage. The real culprits are uncontrolled diabetes and uncontrolled hypertension, which, over time, can damage the kidneys. When kidney function declines, we may have to stop metformin — not because it caused the kidney disease, but because the body may no longer be able to safely clear the medication. If it accumulates, it could (in rare cases) lead to a serious condition called lactic acidosis. This has led to the false belief that metformin caused the kidney failure.

In truth, Metformin is safe for use even in patients with mild to moderate kidney impairment, provided the dose is adjusted and kidney function is monitored regularly. Guidelines now allow Metformin use down to an eGFR of 30, a significant update from the overly cautious restrictions of the past.

Metformin has a long and fascinating history. Its origins trace back to a plant called Galega officinalis, or French lilac, used in medieval Europe to treat diabetes-like symptoms. The active ingredient, guanidine, was the inspiration for the development of metformin, which has been in clinical use since the 1950s.

Today, Metformin is still the most commonly prescribed after diet and exercise are recommended. It works by helping the body use insulin more efficiently and by reducing the liver’s production of sugar. It also has the advantage of not causing weight gain or low blood glucose when taken alone. It can be used on its own or in combination with other oral medicines, injectable medications, or insulin.

Like any medication, Metformin can have side effects. The most common ones are gastrointestinal — nausea, soft stools or a mild upset stomach — especially when first starting. These usually resolve on their own. Taking metformin after meals and starting with a low dose can help ease the symptoms. Extended-release versions may be better tolerated by some patients.

And now for some exciting new research: Recent studies have shown that women taking metformin have a 30 percent higher chance of living to the age of 90. Other trials suggest that metformin may reduce the risk of long Covid and even slow cellular aging. There are ongoing studies looking at Metformin’s use in heart failure, cancer prevention, and even hair loss. It’s far more than just a diabetes drug.

That said, Metformin is not for everyone. Your doctor will consider your overall health, your kidney and liver function, and other medications you’re taking. If you’re seriously ill, dehydrated, or hospitalized, your doctor may advise holding off on metformin temporarily.

So, if you are taking Metformin and doing well — keep taking it. And if you have questions or concerns, don’t rely on TikTok, Facebook, or hearsay. Ask your doctor.

When it comes to your health, science — not fear — should be your guide.