Acute liver injury linked to an adulterated weight-loss product: Integrated clinical, chemical, and toxicological evidence supporting a highly probable causality as assessed by updated RUCAM (2016).

Background: Acute liver injury associated with unregulated products marketed as dietary supplements is an emerging toxicological and public health concern, particularly due to the increasing prevalence of chemically adulterated formulations. Case presentation: A case of severe acute hepatocellular injury with marked aminotransferase elevation following short-term exposure to an Internet-purchased weight loss product is described. Clinical evaluation excluded alternative etiologies, including viral, autoimmune, and structural causes of liver injury. Methods: Causality was prospectively assessed using the updated RUCAM (2016). Chemical characterization was performed using gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES), complemented by in vitro toxicity testing ( Results: The Updated RUCAM assessment yielded a score indicating a highly probable causal relationship between product exposure and liver injury. Analytical profiling has identified multiple undeclared synthetic pharmacologically active substances at supratherapeutic concentrations, confirming product adulteration. The experimental assays demonstrated marked biological activity, supporting the toxicological relevance of these findings. Conclusions: This case highlights the significant hepatotoxic risk associated with chemically adulterated and unregulated weight-loss products. The integration of clinical assessment, advanced analytical chemistry, and experimental toxicology provides a robust translational framework for causal inference in suspected product-related liver injury, and underscores the need for strengthened pharmacovigilance systems targeting illicit or unregulated products.