GLP is a formal FDA regulation created in 1978 that provides principles for conducting laboratory studies in a standard, consistent manner. It aims to ensure quality and integrity of data submitted to the FDA. Key GLP principles include requirements for test facility organization, quality assurance programs, facilities, equipment, test systems, standard operating procedures, study conduct, reporting, and record keeping. GLP helps provide reliable results and protects study integrity and data for regulating products like drugs and pesticides.