For anti-doping screening of athletes, the levels of detection used are measured at the part per billion level (i.e. banned substances need to be detected at the nanogram per ml of urine/ blood level).

By contrast, the supplement manufacturing industry would generally use tests with detection limits in the part per million (i.e. microgram per ml or microgram per gram) range when testing for general contaminants for routine Quality Control purposes. This means that an athlete's urine or blood test is much more sensitive and is more likely to detect the presence of a Prohibited Substance than when a supplement product or ingredient is tested during the manufacturing process using conventional methods, with less sensitive detection levels.

The concentration of the contaminant, expressed in terms of a standard unit (i.e. a gram or ml in this case), is not as relevant as the total intake of a supplement within a daily dose. This may vary from a few grams to perhaps over 100 grams depending on the product. For example, an athlete would consume a greater volume of a supplement by taking one serving of creatine than they would by taking one vitamin tablet. The more one takes, the higher the risk of having traces of a prohibited contaminant in your system.


The levels and limits of analytical detection have profound implications on supplement quality assurance programmes, demanding testing sensitivities that can only be met by highly specialised analytical laboratories, working to ISO 17025 standards. It is extremely uncommon for the manufacturing facilities used by supplement companies to have the capability to undertake such trace analysis in-house, concentrating instead on the verification of label listings of specified contents. In most cases, supplement manufacturers will test products for other contaminants such as toxic substances, heavy metals, etc., and not necessarily for those substances that may give rise to a positive drug test for a professional athlete, such as nandrolone or ephedrine.