Natural body building refers to a category of body building among the different types of body building such as teenage body building and female body building. As the very name suggests natural body building organisations do not promote the use of artificial body muscle enhancers like anabolic steroids and growth hormones by the contestants of their body building competitions. The body builders who use these types of artificial bodybuilding enhancers will not be permitted by these organisations to participate in the bodybuilding competitions.

The contestants of bodybuilding competitions under the organisations will be subjected to medical examinations to rule out the possibility of the usage of banned body building supplements by them. If any of the illegal substances are found in the body of any of the body builder in the drug testing, he will be banned from participating in the future contests of the organisation.

Drug testing of the contestants will normally be conducted by examining the urine samples of the contestants. Some time these organisations opt for a less expensive polygraph test or a lie detecting test instead of the urine examination.

There exists no uniform law that decides as to what constitutes an illegal substance to prevent the contestant from participating in a bodybuilding competition. A substance that is considered as illegal by an organisation or a federation of natural bodybuilding need not be considered as an illegal substance by another organisation. It all depends on the rules of the different federations of natural bodybuilding. Like wise the list of illegal substances need not only be the substances that are illegal under the law of the relevant jurisdiction.

Anabolic steroids, pro hormone and diuretics are the common substances that are banned by such organisations including North American Natural Body Building Federation (NANBF) and Natural Physique Association (NPA).

Drug testing of these natural bodybuilding federations will normally be organised at national level. National drug or anti-doping bodies that organised under the auspices of World Anti- doping Agency (WADA) are often entrusted by these organisations to conduct the drug test on the participants of bodybuilding competitions. These anti-doping agencies approved by the natural bodybuilding federations include Australian Sports Anti Doping Authority (ASADA) and New Zealand Sports Drug Agency (NZSDA).

Like IFBB natural bodybuilding organizations also conduct a number of bodybuilding competitions where a contestant can acquire the rank of natural professional body builder. These competitions are very different to those where there is no type of substance testing so there is much more work which has to go into dropping body fat before the competition to get the definition required.