Growth factors only of glandular origin may be considered hormones. Examples of these types of hormones include the ones in the glands within the endocrine system.

1. In the thyroid gland, hormones such as calcitonin, thyroxine, and triiodothyronine exist. 
1. Thyroxine controls how much energy the body uses (metabolic rate). 
2. Calcitonin helps to regulate calcium levels in the blood by decreasing it. 
2. In the pituitary gland, hormones such as growth hormone, follicle-stimulating hormone, prolactin, and adrenocorticotropic hormone exist. 
1. Growth hormonepromotes growth in children and adolescents. 
2. Prolactin is a polypeptide hormone which is responsible for lactation (breast development) and functions in hundreds of other actions necessary to maintain homeostasis. 
3. Follicle-stimulating hormoneplays a significant role in sexual development and reproduction through affecting the function of the ovaries and testes. 
4. The key function ofadrenocorticotropic hormoneis to stimulate the production and release of cortisol from the cortex of the adrenal gland. 
3. In the adrenal glands, hormones such as aldosterone, epinephrine, and cortisol exist. 
1. Cortisol has a significant role in the stress response of the body, as it works with certain areas of the brain to control mood, motivation, and fear. 
2. Aldosterone regulates the salt and water balance of the body through increasing the retention of sodium and water and the excretion of potassium by the kidneys. 
3. Epinephrine plays a significant role in the body’s fight-or-flight response. 

It is important to note that the production of hormones is limited to glandular tissue, while growth factors may be produced by many different types of tissues.