Adverse Effects and Patient Perceptions of Unregulated Arthritis Supplements: A Retrospective Mixed-Methods Study at a Safety-Net Primary Care Clinic

Introduction The use of complementary and alternative medicine is prevalent among individuals living with chronic pain. Artri King and similarly branded over-the-counter supplements are advertised as natural arthritis pain relievers but have been found to contain hidden prescription drugs including dexamethasone, diclofenac, and methocarbamol. These unbranded pharmaceutical agents may pose significant health risks, particularly when used without clinical oversight or in combination with other therapies. This study sought to understand patient experiences, perceptions, and motivations for using these supplements despite FDA warnings and the associated potential for harm. Materials and methods Between April 2024 and March 2025, clinicians at an urban, academic safety-net primary care clinic in California identified patients who reported using over-the-counter arthritis pain supplements. Clinical data were extracted from the electronic health record. Semi-structured phone interviews were conducted to assess patient-reported motivations, product understanding, duration, dosage, quantity of use, symptom relief, and side effects. Results Clinicians identified 14 patients taking arthritis pain supplements reported by the FDA as containing undisclosed drugs (Artri King, Artri Ajo King, RM Flex); 12 of these patients completed phone interviews for this study. Motivations for supplement use included word-of-mouth recommendations, inadequate pain relief from prescribed treatments, and the belief that the supplements were "natural" and therefore safe. All patients reported significant pain relief. None were aware of the presence of hidden ingredients or the potential for adverse effects. Over half of the patients reported side effects. Of the five patients who underwent morning cortisol testing, three had levels consistent with adrenal insufficiency. Additional adverse events during the period of supplement use included cardiovascular and gastrointestinal complications. Of the 12 patients interviewed, 11 discontinued the supplement, of whom 8 stopped after recommendation from their physician. Conclusion Despite FDA warnings, patients with chronic musculoskeletal pain continue to use over-the-counter arthritis supplements due to community recommendation, perceived safety of the supplement, and limited relief from conventional therapies. Many are unaware of hidden pharmaceutical ingredients and experience serious adverse effects. Clinicians should routinely screen for supplement use, particularly in high-risk populations; provide clear, empathetic education about potential risks; and discuss safer pain management strategies.