POMC and Adrenal insufficiency: Although serum cortisol testing ± the ACTH stimulation test are considered the gold standards for the diagnosis of true adrenal insufficiency, it is important to note that the use of steroid therapy or opioids [11-15] suppresses ACTH and cortisol production and produces reversible adrenal insufficiency; in my experience, steroid and opioid use is common among people with “adrenal fatigue.”