REGULATION (EU) No 536/2014

https://ec.europa.eu/health/sites/health/files/files/eudralex/vol-1/reg_2014_536/reg_2014_536_en.pdf

‘Clinical study’ means any investigation in relation to humans intended:
  (a) to discover or verify the clinical, pharmacological or other pharmacodynamic effects of one or more medicinal products;
  (b) to identify any adverse reactions to one or more medicinal products; or
  (c) to study the absorption, distribution, metabolism and excretion of one or more medicinal products;
  with the objective of ascertaining the safety and/or efficacy of those medicinal products;