In March 2026, the journal Frontiers in Sports and Active Living published a systematic review summarizing data on the presence of undeclared prohibited substances in dietary supplements used in sports. The study covers scientific publications from 2010 to 2025 and demonstrates that supplement contamination is a systemic and global issue.

According to the authors, an estimated 9% to 15% of commercially available supplements may contain undeclared prohibited or pharmacologically active substances. This is not an isolated occurrence but a persistent trend observed across multiple countries and product categories.

Substances from nearly all classes of the WADA Prohibited List have been detected in such products, including anabolic steroids, stimulants, selective androgen receptor modulators (SARMs), hormonal and metabolic modulators, diuretics, beta-blockers, and other compounds. A significant proportion of these substances are not listed on the product label, creating a direct risk of unintentional anti-doping rule violations.

The highest risk is associated with pre-workout complexes, energy products, muscle-building supplements (especially those labeled “testosterone” or “anabolic”), and weight-loss products. These categories most frequently show evidence of adulteration or the addition of pharmacologically active ingredients.

The practical implications of these findings for athletes are clear: even legally purchased supplements do not guarantee safety under anti-doping rules. The presence of undeclared components may result in a positive doping test, sanctions, and potential harm to health.

In this context, the principle of strict athlete liability remains paramount. No reference to the manufacturer or product labeling absolves an athlete of responsibility for the substances found in their body.

Accordingly, the sports community should consider dietary supplement use as a factor of increased risk. The National Anti-Doping Center urges athletes to exercise maximum caution with supplements and, whenever possible, to avoid their use unless genuinely necessary. Even legal products may contain prohibited substances, meaning any supplement use carries a risk of anti-doping rule violations.

Clean sport is your responsibility!