Glucocorticoid-induced adrenal insufficiency from a supplement containing undisclosed dexamethasone

Glucocorticoid-induced adrenal insufficiency (GIAI) is a very common cause of adrenal insufficiency, resulting from exogenous glucocorticoid exposure leading to suppression of the hypothalamic-pituitary-adrenal axis. While typically due to prescribed glucocorticoids, hidden ingredients in supplements may also contribute to this exposure. We describe a case of a 52-year-old male who presented with recurrent gastrointestinal symptoms of nausea and vomiting. Clinical features included persistent sinus tachycardia, hyponatremia, hypokalemia, and hypomagnesemia. The initial work-up was unrevealing; additional testing revealed a low random cortisol level, an inadequate response to cosyntropin stimulation, and an inappropriately normal adrenocorticotropic hormone level, confirming secondary adrenal insufficiency. Treatment with hydrocortisone resulted in improvement of the patient's clinical symptoms. Further history uncovered that the patient had abruptly discontinued a daily supplement named "Force Forever," which, according to the US Food and Drug Administration (FDA), contains undisclosed ingredients, including diclofenac and dexamethasone. Although the FDA has issued a warning regarding this supplement, there have been no reported cases of GIAI from its use in the United States. This case emphasizes the importance of comprehensive history taking and considering adrenal insufficiency in the differential diagnosis for patients presenting with refractory, unexplained gastrointestinal symptoms like nausea and vomiting.