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Whey protein-based supplements are one of the most consumed products to improve performance, and they are, generally, recognized as being safe. However, recent studies indicated different types of adulterations in these products, including the presence of diuretics and stimulants, allowing the possibility of contamination by other substances with pharmacological activities, such as anabolic agents. In this sense, the aim of this study was to develop and validate a method for the screening of 46 anabolic agents in whey protein. The analytical method consisted of sample preparation using liquid-liquid extraction, followed by analytes derivatization and, finally, analysis by gas chromatography coupled to triple quadrupole mass spectrometry in two different experiments: multiple reaction monitoring and full scan. After validation, the method proved to be specific, accurate, and precise; no carry over effect was observed, and the limit of detection values varied between 0.5 and 100 ng g−1. The analysis of 44 commercial samples did not detect the presence of any anabolic agent. However, full scan analysis detected caffeine in 14 samples and bisphenol A in one of them. Therefore, these results indicate that the analyzed samples are safe concerning the presence of the evaluated anabolic agents, but it does not mean that they are free from the presence of other substances with pharmacological activities which are not declared on label. [ABSTRACT FROM AUTHOR]

N, N-dimethyl-2-phenylpropan-1-amine (NN-DMPPA) is a new designer stimulant prohibited in sport in-competition according to the List of Prohibited Substances and Methods published by the World Anti-Doping Agency (WADA). The first published data on the excretion study of NN-DMPPA to support the knowledge of NN-DMPPA in routine anti-doping control have been presented. The reliable gas chromatography-mass spectrometry quantitative method (GC-MS) has been validated and applied to the excretion study of NN-DMPPA. The validation parameters of the GC-MS method for determination of NN-DMPPA in human urine were the linear calibration range of 100 to 7500 ng/mL, the LOD of 13.9 ng/mL and the LOQ of 42.2 ng/mL. According to the obtained repeatability, intermediate precision, and trueness, the applied GC-MS method was precise and accurate. Urine samples from three volunteers in the excretion study were collected for 5 days after single oral administration of the supplement NOXPUMP containing NN-DMPPA. The obtained results showed the maximum concentration of NN-DMPPA (189-303 ng/mL) in urine samples at a time of 2-3 h post-administration. The NN-DMPPA concentration in urine samples was higher than 50 ng/mL until 22-23 h after the dietary supplement ingestion. This means that according to the WADA rules the use of a supplement containing NN-DMPPA may be related to a positive case when athletes took this supplement in-competition. Moreover, excretion results demonstrate also that NN-DMPPA may be detected in urine samples by the applied GC-MS method till 46 h after supplement administration. Additionally, the excretion study of β-methylphenethylamine as the second prohibited substance present in the supplement NOXPUMP has been investigated. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Herbal and nutritional supplements are more and more popular in the western population. One of them is an extract of an exotic plant, named Tribulus terrestris (TT). TT is a component of several supplements that are available over-the-counter and widely recommended, generally as enhancers of human vitality. TT is touted as a testosterone booster and remedy for impaired erectile function; therefore, it is targeted at physically active men, including male athletes. Based on the scientific literature describing the results of clinical trials, this review attempted to verify information on marketing TT with particular reference to the needs of athletes. It was found that there are few reliable data on the usefulness of TT in competitive sport. In humans, a TT extract used alone without additional components does not improve androgenic status or physical performance among athletes. The results of a few studies have showed that the combination of TT with other pharmacological components increases testosterone levels, but it was not discovered which components of the mixture contributed to that effect. TT contains several organic compounds including alkaloids and steroidal glycosides, of which pharmacological action in humans is not completely explained. One anti-doping study reported an incident with a TT supplement contaminated by a banned steroid. Toxicological studies regarding TT have been carried out on animals only, however, one accidental poisoning of a man was described. The Australian Institute of Sport does not recommend athletes' usage of TT. So far, the published data concerning TT do not provide strong evidence for either usefulness or safe usage in sport. [ABSTRACT FROM AUTHOR]