Low Cortisol in a Cushingoid Patient

A 52-year-old woman presented with symptoms consistent with Cushing syndrome, such as weight gain, facial hair growth, and easy bruising, but had unexpectedly low serum cortisol levels. Further investigation revealed that she had been unknowingly ingesting dexamethasone, a potent synthetic glucocorticoid, through a dietary supplement not listing it as an ingredient. This hidden dexamethasone caused her Cushingoid symptoms and suppressed her ACTH and cortisol levels, leading to diagnostic confusion. The case highlighted the potential dangers of unregulated supplements containing undisclosed prescription drugs, which can result in misleading clinical and laboratory findings.