Context: With the increasing use of unregulated dietary supplements, athletes are at continued risk from adverse medical events and inadvertent doping.
Evidence acquisition: A review of Clinical Key, MEDLINE, and PubMed databases from 2012 to 2017 was performed using search terms, including dietary supplement, contamination, doping in athletes, inadvertent doping, and prohibited substances. The references of pertinent articles were reviewed for other relevant sources.
Study design: Clinical review.
Level of evidence: Level 3.
Results: Poor manufacturing processes and intentional contamination with many banned substances continue to occur in dietary supplements sold in the United States. Certain sectors, such as weight loss and muscle-building supplements, pose a greater threat because they are more likely to be contaminated.
Conclusion: Athletes will continue to be at risk for adverse events and failed doping tests due to contaminated dietary supplements until legislation changes how they are regulated. In the interim, there are several steps that can be taken to mitigate this risk, including improved education of medical staff and athletes and use of third party-certified products.
Keywords: dietary supplements; inadvertent doping; prohibited contaminants.