Uncovering adulteration in Tribulus terrestris supplements using LC-MS-based metabolomics

Tribulus terrestris dietary supplements are widely consumed for their purported health benefits, yet concerns persist regarding product authenticity and the potential for adulteration. In this study, an untargeted liquid chromatography-high-resolution mass spectrometry (LC-HRMS) metabolomics approach was employed to investigate the composition of T. terrestris -derived supplements. The analysis encompassed authentic plant materials, intentionally adulterated samples, and commercially available products. Data interpretation using principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and a convolutional neural network tool enabled the differentiation of sample groups and identification of irregularities. The presence of pharmacologically active adulterants, including PDE5 inhibitors and anabolic steroids, was confirmed in spiked samples. Furthermore, certain commercial products were found to contain undeclared compounds derived from green tea and citrus, presumably added to enhance stimulant effects and reinforce testosterone-related claims. Spirost-4-ene-3,12-dione was detected as a potential marker of steroidal saponin degradation, likely linked to improper storage or processing. These findings underscore the effectiveness of LC-HRMS-based metabolomics in detecting supplement adulteration and highlight the pressing need for stringent quality control measures to ensure consumer safety and product authenticity [ 1 ]. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany