Metformin inactive ingredients?

What are metformin’s inactive ingredients?

Metformin tablets and extended-release metformin ER tablets do not use the exact same inactive ingredients in every product. The “inactive ingredients” (also called excipients) can vary by manufacturer and by formulation strength (immediate-release vs extended-release). To see the exact inactive ingredients for a specific metformin product, check the label section titled “Inactive ingredients” (often listed on the manufacturer’s prescribing information or patient leaflet).

Why do metformin inactive ingredients differ between IR and ER?

Extended-release (ER) metformin tablets typically use a different set of excipients than immediate-release tablets because ER products rely on special materials to slow drug release. That means you can see differences in ingredients such as tablet coatings, matrix materials, and fillers/binders between IR and ER versions—even when the active ingredient (metformin) is the same.

Where can you find the exact inactive ingredient list for your metformin?

Look up your specific product (brand or generic label) and formulation type:
- Immediate-release (IR) metformin tablet vs extended-release (ER) metformin tablet
- Strength (for example, 500 mg, 850 mg, 1000 mg)
- Manufacturer (the label usually shows this)

If you share the exact product name and strength (or upload the label), I can help you identify the inactive ingredient list for that specific one.