MHRA Monitoring Metformin Contamination

Tim Locke

December 09, 2019

The UK's Medicines and Healthcare products Regulatory Agency (MHRA) is working with other drugs regulators around the world over reports of possible carcinogenic impurities in metformin.

Investigations are already underway by the US FDA and the European Medicines Agency (EMA).

In a statement the MHRA said it was "aware that outside the UK very low amounts of an impurity, N-nitrosodimethylamine (NDMA), have been found in some metformin diabetes medicines".

It continued: "The levels of NDMA seen in the affected non-UK metformin medicines are very low and appear to be within or even below the range that people would normally be exposed from other sources, including food and water."

Patients are being advised to continuing taking their medication because the risks of stopping diabetes treatment outweigh risks due to contamination. GPs, diabetes specialists, nurses, and pharmacists can expect questions from some patients after the MHRA said patients with concerns should talk to their healthcare professional.


NDMA impurities have been implicated in the recent recalls of batches of ranitidine and sartan medications.

The EMA said: "NDMA is classified as a probable human carcinogen on the basis of animal studies. It is present in some foods and in water supplies, but it is not expected to cause harm when ingested in very low levels."

The EMA said that currently there is no evidence indicating that EU metformin medicines are affected.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: