Nitrosamines are chemical compounds classified as probable human carcinogens based on animal studies. This means that long-term exposure above certain levels may increase the risk of some cancer. There is a very low risk that nitrosamine impurities at the levels found in medicines could cause cancer in humans.
EU regulators first became aware of nitrosamines in medicines in mid-2018 when nitrosamine impurities, including N-nitrosodimethylamine (NDMA), were detected in blood pressure medicines known as 'sartans'.
Scientific experts from the EU Network carried out a review of these impurities under Article 5(3) of Regulation (EC) No 726/2004. They provided guidance for marketing authorisation holders to avoid the presence of nitrosamine impurities in their medicines.
Marketing authorisation holders are responsible for ensuring that every batch of their finished product is of satisfactory quality. This includes the raw materials like active substances and other ingredients used to make them. They should follow the guidance, consider their manufacturing processes and use all relevant scientific evidence.
EMA continues to work closely with the EU national authorities, the European Directorate for the Quality of Medicines & HealthCare (EDQM), and international partners to ensure companies take appropriate measures to limit nitrosamine impurities in their products.
For more information on referral procedures for human medicines, see:
A report is available outlining the the European medicines regulatory network’s response to nitrosamine impurities in human medicines.
The report summarises the scientific and regulatory milestones since the discovery of nitrosamine impurities in 2018. These impurities were detected in a group of cardiovascular medicines known as 'sartans' and later also in other medicines.
The report:
EMA and CMDh produced this report jointly, and published it in July 2025.