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This glossary gives definitions for the main regulatory terms used on this website and in European Medicines Agency (EMA) documents.

Click on a letter below to see terms beginning with that letter.

Disclaimer: EMA has developed the definitions in this glossary to help this website's users understand regulatory terminology. Definitions may differ from those given in European Union legislation.


safety signal

Information on a new or known adverse event that is potentially caused by a medicine and that warrants further investigation. Signals are generated from several sources such as spontaneous reports, clinical studies and the scientific literature.

For more information, see Signal management.

scientific advice

The provision of advice by the European Medicines Agency on the appropriate tests and studies required in the development of a medicine or on the quality of a medicine.

For more information, see Scientific advice and protocol assistance.

scientific advisory group

A group of European experts brought together to provide advice in connection with the evaluation of specific medicines.

For more information, see Working parties and other groups.

serious adverse reaction

An adverse reaction that results in death, is life-threatening, requires hospitalisation or prolongation of existing hospitalisation, results in persistent or significant disability or incapacity, or is a birth defect.

somatic cell based medicine

A medicine containing cells or tissues that have been manipulated to change their biological characteristics, which is used to cure, diagnose or prevent a disease.

For more information, see Advanced therapies.

specific obligations

Requirements imposed on holders of conditional marketing authorisations or marketing authorisations granted under exceptional circumstances.

For more information, see Follow-up measures / specific obligations: questions and answers.


A sample of the actual printed outer and inner packaging materials and package leaflet for a medicine.

For more information, see Mock-ups and specimens.

subgroup analysis

The separate analysis of clinical trial results in subsets of the trial’s participants.

For more information, see Methodologies and statistics.

summary of opinion

A document summarising the opinion issued by one of the European Medicines Agency's committees at the end of the evaluation process.

summary of product characteristics

A document describing the properties and the officially approved conditions of use of a medicine. Summaries of product characteristics form the basis of information for healthcare professionals on how to use the medicine safely and effectively. Abbreviated as SmPC.

For more information, see Product information requirements and Guideline on summary of product characteristics.

sunset clause

A legal provision stating that the marketing authorisation of a medicine will cease to be valid if the medicine is not placed on the market within three years of the authorisation being granted or if the medicine is removed from the market for three consecutive years.

For more information, see Sunset clause monitoring: questions and answers.

supplementary protection certificate

A means of extending the term of patent exclusivity for a new medicine for a fixed period from the date of the first marketing authorisation in a European Union Member State.