Metformin: What It Does and What to Expect

Metformin is the medicine most people with Type 2 diabetes are given first, and it has been in use for decades.

It works in two ways. It tells your liver to release less glucose into your blood — your liver makes glucose on its own, which is why fasting readings can be high even when you have not eaten. And it helps your body use its own insulin better. It may also help you lose a small amount of weight.

Importantly, metformin does not push your pancreas to make more insulin, which is why it does not usually cause low blood sugar on its own.

The common problem in the first few weeks is the stomach — loose motions, nausea, a metallic taste. This usually settles. Taking it with food helps a lot, and starting at a low dose and building up helps more. If it does not settle, ask about the extended-release version, which many people tolerate better.

Taking it correctly matters here — see timing, food and missed doses. And do not stop it because of early side effects without talking to your doctor. Stopping a medicine that is working, because of something that would have passed in two weeks, is a common and avoidable setback.