Over Half of the Dietary Supplement Products Linked to Liver Injury May be Mislabeled

Reviewed: Navarro V, Avula B, Khan IA, Verma M, Seeff L, Serrano J, Stolz A, Fontana R, Ahmad J. The contents of herbal and dietary supplement implicated in liver injury in the United States are frequently mislabeled. Hepatol Commun. 2019;3(6):792-794.

Keywords: Adulteration, conventional drug, dietary supplement, HPLC-QTOF-MS, liver injury

The Drug-Induced Liver Injury Network (DILIN) is a multicenter consortium funded by the National Institute for Diabetes and Digestive and Kidney Disease (NIDDK). Some of the activities of the DILIN are focused on the possible link between dietary supplement intake and the liver injury risk. In the 12 years from 2003-2015, the network collected 341 products labeled as dietary supplements from 1268 patients with suspected drug-induced liver injury. Of these 341 products, only 272 had ingredients listed; these 272 products were analyzed by high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) to find ions that would allow the identification of labeled and unlabeled ingredients in these products.

Based on the MS results, 132 products were accurately labeled, while the remaining 140 products had at least one ingredient missing, with 55 products also having additional ingredients that were not declared on the label. Label inaccuracy was particularly high in erectile dysfunction (100%), performance enhancing (80%), and energy supplements (60%). A total of 44% of botanical dietary supplements were mislabeled according to the study. The adulterants were not identified except in cases when undeclared steroids (present in 13 performance-enhancing products) or prescription drugs (diclofenac, tamoxifen) were found. The presence of these undeclared ingredients was consistent with the clinical features of liver injury observed in the patients.

Comment: This publication highlights the importance of proper analytical characterization of dietary supplement products when assessing the causative agents in adverse event reports. A few of the ingredients causing liver injury were anabolic steroids or prescription drugs in preparations masquerading as dietary supplements. The paper lacked some basic information, such as the total number and type of botanical dietary supplements analyzed, and details on the analytical method. A list of all the undeclared materials detected in the 55 dietary supplements where such ingredients were found would have been valuable for further assessment of the potential liver toxicity of these adulterants.

While the number of products missing one or more declared ingredients is high, the absence of marker compounds for a specific botanical/dietary ingredient may be due to the fact that some of the products were over a decade old, and marker compounds may have degraded over time. A bit confusing is the abbreviation “HDS” used by the authors for “herbal and dietary supplements”, as HDS is commonly used for “herbal dietary supplements” and therefore tends to suggest that the products involved in these liver injury cases were all botanically based, when in fact they were not. Nevertheless, a label accuracy of 44% for the analyzed botanical dietary supplements is simply unacceptable.