Natural bodybuilding is the practice or participation in bodybuilding competition without the use of banned substances (most commonly referring to the use of illegal performance-enhancing drugs, such as anabolic steroids, human growth hormone, insulin and exotic plant extracts such as: tribulus terrestris).
Natural Bodybuilding has many organizations with competitions where one can earn the rank of a natural professional bodybuilder. Professional natural bodybuilding organizations include the PNBA (Professional Natural Bodybuilding Association), professional affiliate of the INBA, IFPA (International Fitness and Physique Association), professional affiliate to the OCB and NANBF, WNBF (World Natural Bodybuilding Federation), professional affiliate to the INBF, and Musclemania and NGA, professional affiliates to their counterpart amateur organizations of the same name.