Biotin is a common supplement sold in most stores. It can help the thyroid as well as the adrenal glands. Many integrative physicians discuss adrenal fatigue too loosely. Some of the symptoms include insomnia, chronic pain, headaches, low libido, anxiety, weight gain, inflammation, addictions, and cardiac issues such as blood pressure and heart disease.
These symptoms can also sound like hypothyroidism. Many people with adrenal fatigue have hypothyroidism. The adrenals are not often tested.
I feel it is not even recognized in most of the literature. You must ask your doctor to do testing of cortisol levels. This is best accomplished through saliva testing (which is not available in all states). The advantage of saliva testing is that it takes cortisol levels at different times of the day and shows how cortisol levels vary.
Adrenal fatigue can be treated with adaptogenic herbs. Some of these herbs include Ashwaghanda, Rhodiola, Holy Basil, and Schisandra.