The adrenal glands don’t really get ‘tired’ in the way that you might expect. What happens is that, after a period of chronic stress, your body starts to run out of the hormone precursor material that it uses to make certain hormones. As this continues, it becomes more and more difficult for your body to produce the required levels of stress hormones, sex hormones, and other hormones and neurotransmitters. That’s when the ‘fatigue’ starts to kick in, and that’s when you need to offer your body some extra support.
Catecholamines are produced in chromaffin cells in the medulla of the adrenal gland, from tyrosine , a non-essential amino acid derived from food or produced from phenylalanine in the liver. The enzyme tyrosine hydroxylase converts tyrosine to L-DOPA in the first step of catecholamine synthesis. L-DOPA is then converted to dopamine before it can be turned into noradrenaline. In the cytosol , noradrenaline is converted to epinephrine by the enzyme phenylethanolamine N-methyltransferase (PNMT) and stored in granules. Glucocorticoids produced in the adrenal cortex stimulate the synthesis of catecholamines by increasing the levels of tyrosine hydroxylase and PNMT.