Propofol is the most widely used intravenous (IV) anesthetic agent for induction and maintenance of anesthesia as well as for sedation. Being an almost ideal IV anesthetic agent, the pain on its injection still remains a problem.

Introduction of several new formulations and hundreds of clinical trials have failed to find its remedy with just one intervention in all patients. In the light of above, what can be the possible reasons for having pain on Propofol injection?