To summarize the maintenance of homeostasis in our body in terms of signal transduction, there are two major axes: the autonomic nervous system and hormones. The autonomic nervous system, one of the peripheral nerves, secretes neurotransmitters such as norepinephrine and acetylcholine to affect target organs quickly and efficiently. Hormones can be viewed as signals that trigger larger changes in the DNA level after they are secreted into the blood and reach target cells. The autonomic nervous system plays the role of a fine screw that regulates the body s functions according to internal and external stimuli, while hormones play the role of a coarse screw. The autonomic nervous system plays the role of a fine screw that fine-tunes the body s functions according to internal and external stimuli, while hormones play the role of a coarse screw. Adrenal hormones are involved in the circadian cycle and vitality of life, and most actively cope with stress and external changes. It can also affect other hormones such as thyroid hormones, sex hormones, and insulin, and also interacts with the autonomic nervous system in the pituitary gland. In the past, growth hormone supplementation therapy was the main concern in the field of anti-aging medicine, but recently, research on the interaction between other hormones has become an important issue. Therefore, this review aimed to examine the integrated understanding and academic basis for the interaction between thyroid hormone, insulin, sex hormone, and neurotransmitter, focusing on adrenal hormone.