Companies Recall Extended-Release Metformin due to Cancer-Causing Substance

By Nena Kotsalidis and Rosalind Lucier

The FDA has announced that 14 companies have voluntarily recalled their extended release metformin due to the possibility that it includes unsafe levels of NDMA, a toxic substance.

Editor's note: This article was first published on July 15, 2020 and has since been updated to reflect the latest recalls.

Earlier in 2021 the FDA raised concerns about the safety of metformin; since then, 14 companies have voluntarily recalled the medication, due to possibly unsafe amounts of a substance called N-nitrosodimethylamine (NDMA). Low levels of NDMA are commonly found in foods and drinking water, but high levels of the substance are toxic and can cause cancer. The FDA answers the most common questions about the NDMA found in metformin products here.

On December 28, 2021 as a precautionary measure, Viona Pharmaceuticals recalled 33 additional lots of metformin extended-release USP 750 mg tablets. Talk with your healthcare provider about whether or not you should stop taking your metformin based on this recent recall. 

Back in June 2020 several companies recalled their ER metformin: Apotex Corp, Teva (labeled as Actavis), Amneal, Lupin, and Marksans (labeled as Time-Cap Labs Inc.) recalled metformin hydrochloride ER tablet, USP 500 mg and 750 mg. Now, fourteen companies have voluntarily recalled some or all of their ER metformin – see the full list:

• Amneal Pharmaceuticals

• Apotex Corp

• Avkare (repackages medications for Amneal)

• Bayshore Pharmaceuticals

• Granules Pharmaceuticals

• Lupin Pharmaceuticals

• Marksans Pharma Limited

• Nostrum Laboratories

• PD-Rx Pharmaceuticals (repackages medications for Amneal and Marksans)

• Preferred Pharmaceuticals (repackages medications for Marksans)

• Sun Pharmaceuticals

• Teva Pharmaceuticals

• The Harvard Drug Group (repackages medications for Apotex)

• Viona Pharmaceuticals

You can check to see if your metformin has been recalled here. For people taking ER metformin, the FDA recommends that you continue to take your medication until you talk to your healthcare professional. Your healthcare professional can help you find different treatment options. It is not safe to stop taking your ER metformin without instructions from your healthcare team.

This recall only applies to ER metformin. If you are currently taking immediate release (IR) metformin, you can continue to take your medication safely. The FDA has not found high NDMA levels in the more commonly prescribed immediate release (IR) metformin products.

Metformin is commonly used to help people with type 2 diabetes manage their blood sugar levels. It is considered a safe, cheap and effective medication worldwide. For more information about metformin, read our detailed piece here.