The Short Version
Every major medical authority — including the Endocrine Society, NIDDK, Mayo Clinic, and Cleveland Clinic — explicitly states that "adrenal fatigue" is not a recognized medical diagnosis and lacks scientific proof. A 2016 systematic review in a peer-reviewed journal found no substantiation for the concept. While adrenal insufficiency (e.g., Addison's disease) is a real condition involving low cortisol, it has distinct causes unrelated to the "overworked adrenals" mechanism described in the claim. The only sources supporting the claim come from low-authority integrative or commercial health websites.