In recent years, increasing concerns have emerged regarding athletes being exposed to various sources of
contamination that could result in an adverse analytical finding (AAF), which is considered a positive doping test
and may lead to the athlete’s sanction. This review aims to examine the potential sources of contamination.
Firstly, exogenous sources such as food, water, supplements, and medications will be described, along with
endogenous sources, primarily arising from the athlete’s physiological condition via the biotransformation of
Medications. Finally, other hypothetical contaminations arising from sample collection procedures, poor transport
or storage, and laboratory conditions will be discussed. Despite some legislative efforts to regulate the
production of food and supplements, contamination remains a significant concern in the context of anti-doping,
necessitating athletes to stay vigilant against the risks of inadvertent uptake of illicit products. Increased
knowledge of the potential sources of contamination is essential for all parties involved in the fight against
doping, including athletes, support personnel, legitimate supplement product manufacturers, and the anti-doping
and scientific community. Such insights can contribute to developing the most effective strategy for preventing
contamination and, most importantly, reducing the risk of inadvertent AAFs.