The NFLs PED (Performance Enhancing Drug) policy prohibits the use of steroids, anabolics, and exogenous testosterone in players. The policy also includes testing for banned substances through random or scheduled urine samples, with a majority of positive cases resulting from these checks. The policy also includes Carbon Isotope Ratio (CIR) testing to detect the use of exogenous steroids and confirmation of the exogenous administration of testosterone. The NFL also has a separate policy for substances of abuse, which covers anything recreational or non-approved medicinally. The policy requires players to update Dr. Lombardo through the PES website and keep copies of travel documentation for four months after their trip. If a player has been or is seeking to be treated by a physician with a banned substance for any condition, they must have their physician file a TUE (Therapeutic Use Exemption) application with the Independent.