Pharmacists are healthcare professionals with specialized education and training who perform various roles to ensure optimal health outcomes for their patients through the quality use of medicines. Pharmacists may also be small-business proprietors, owning the pharmacy in which they practice. Since pharmacists know about the mode of action of a particular drug, and its metabolism and physiological effects on the human body in great detail, they play an important role in optimization of drug treatment for an individual. Pharmacists are represented internationally by the International Pharmaceutical Federation (FIP). They are represented at the national level by professional organisations such as the Royal Pharmaceutical Society in the UK