Athletes using supplements may lead to a positive test result due to the following reasons:
1. Inaccurate labelling
The labeling of supplements is not strictly regulated. Intentionally or not, there is a possibility that not all of the ingredients are listed on the supplements labels and the undeclared ingredients may contain prohibited substances.
2. Contamination during production
Since the manufacturing of supplements is not strictly regulated, supplements may be contaminated with prohibited substances during production.
It is virtually impossible to confirm that a supplement does not contain any prohibited substances. Athletes should seriously assess the risk of using a supplement.