Drug safety (Pharmacovigilance)

Drug safety, or pharmacovigilance, experts monitor unexpected side effects of medicines during clinical trials and once the medicine is marketed.

Working in drug safety

​No medicine is 100% safe. Drug safety is the science of detection, assessment, understanding and prevention of side effects which allows us to understand more about the risks and benefits of a medicine.

Drug safety scientists collect and evaluate information from patients and healthcare professionals, working to identify new information about the use of medicines and any side effects experienced by patients.

Safety monitoring of medicines is a continuous process, it is performed during clinical trials when medicines are developed, once medicines are launched (also called ‘licenced’) and throughout the entire period where a medicine is available for patients to use. Medicines are often taken by large numbers of people and side effects that are rare can sometimes only be detected once a medicine has been marketed. Individual patients and healthcare professionals are encouraged to report any side effects they experience via the Medicines and Healthcare Products Regulatory Agency's (MHRA) Yellow Card reporting scheme or directly to the company that manufacture the medicine. 


The techniques used to monitor medicine safety range from the investigation of individual case reports, to data mining in large databases and epidemiology. This information is used to ensure the safe use of medicines and prevent harm to patients, and often results in an update of the side effects for a medicine detailed in the leaflet.

  • Reporting of individual case reports to regulatory agencies
  • Preparation of summaries of product safety at specified intervals
  • Preparation of risk management plans which contain actions (which can include epidemiological studies) to further characterise risks associated with medicines and ensure actions are in place to minimise risks when they have been detected

Some companies employ specialist pharmacovigilance professionals to ensure that drug safety is carefully monitored and considered, whereas in other companies the role can be combined with medical information teams. 

For further information, see the MHRA learning module on Pharmacovigilance.

You can also take a look at this case study of a real Pharmacovigilance Scientist working in the industry.

Last modified: 02 May 2024

Last reviewed: 02 May 2024