Experiences of testing dietary supplements

Sunday, June 30, 2019

Authors: Erika Horváthné Soós, Gábor Garai, Eszter Dési, Tamás János Szigeti


Determination of the prohibited active ingredients, such as drugs and their designer compounds, of dietary supplements products intended for athletes is an important,but not yet well-known and regulated area of food analysis.

In our laboratory, the analysis of three major product groups is carried out. The first group includes products intended for athletes. They can be dietary supplements or a group of products that had been classified as foodstuffs for particular nutritional uses before 2016, for example, high protein content products promoting great muscular effort, intended primarily for athletes and workers performing heavy labor, which were transferred to the category of dietary supplements or normal foods after 2016. For athletes, when consuming the products, in addition to preserving health and the physiological effects to be achieved, it is important that the products do not containeven trace amounts of substances that are on the prohibited list of WADA (the World Anti-Doping Agency), because they are solely responsible for the presence of these in their bodies.

The second group is that of weight loss products. Regarding the prohibited substances used in dietary supplements, products belonging to this group show a high degree of similarity to the group of products containing stimulants prohibited for athletes.
The third group consists of products used for the treatment of sexual dysfunctions. In these, phosphodiesterase inhibitors, widely known as drugs, may be present as prohibited active ingredients or contaminants. The most common ingredients of these products include plant extracts.
In all three cases, the extent of contamination may vary widely in the groups examined, from trace amounts to pharmaceutical active ingredient levels.
12 years ago, when the analysis of products has been started at our laboratory intended for athletes, our objective was to develop screening analytical methods that are able to determine prohibited stimulants with detection limits of 100 ng/g and anabolic agents with detection limits of 10 to 50 ng/g efficiently, in a robust way, with sufficient measurement (detection) accuracy. The analysis of potency enhancers was launched three years later. Since the initial analysis of 40 components, the number of types and components of active ingredients analyzed has increased significantly and, in addition, in the case of stimulants and narcotics, the detection limit improved to 10 ng/g. Currently, accredited analysis of 126 prohibited ingredients is performed in the laboratory. During this time, more than 10,000 raw materials and finished products have been tested. For the analysis of anabolic agents, hormone and metabolic modulators, GC-MS and LC-MS/MS methods have been used, while LC-MS/MS techniques have been used for the determination of stimulants, narcotics, beta-blockers, beta2 agonists and potency enhancers, following appropriate sample preparation.

In our manuscript, of the compound groups examined in the laboratory, the analyses of anabolic agents and aromatase inhibitors, which belong to the group of hormone and metabolic modulators, are presented, in products intended for athletes and their raw materials.
It should be noted that for the names of the compounds in dietary supplements contained in this paper, the Anglo-Saxon version common in international practice is used.


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