Metformin: 3 warning signs to know

Metformin is one of the most prescribed medications for type 2 diabetes, but like any medication, it isn't perfect.

The most common side effects include:

• Diarrhea
• Nausea
• Stomach upset
• Gas and bloating

The good news? Many of these symptoms improve over time and may be reduced by taking Metformin with food or using an extended-release version.

There are also a few important things to watch for:

• Vitamin B12 deficiency with long-term use
• Kidney function monitoring
• Rare but serious risk of lactic acidosis

As a pharmacist, I'll explain what side effects are common, what side effects are rare, and when you should contact your healthcare provider.