The pineal gland is responsible for regulating melatonin. It is not known at this time to secrete any other hormone. Melatonin is thought to play a critical role in the regulation of the circadian rhythm. Cortisol is secreted by the adrenal cortex and is involved in regulating the stress response. Vitamin D become activated in three steps. First, ultraviolet light in the skin begins the process, then the process continues in the liver, and is completed in the kidney. The active form of vitamin D increases calcium absorption in the gut, decreases calcium loss in urine, and increases calcium mobilization from bone. Vasopressin is also known as antidiuretic hormone, and functions in water retention. Leptin is a hormone secreted by adipose tissue that tells the body that it is full, and not hungry.

Endocrine glands secrete hormones into the blood. The endocrine glands include the ovaries, testes, hypothalamus, thyroid, pituitary, adrenal glands, pancreas, the pineal gland, and others. Salivary glands are considered exocrine glands. Exocrine glands secrete substances through ducts to the body surface or into body cavities, such as the mouth in the case of salivary glands.

Catecholamines are hormones produced by the adrenal medulla. Adrenal glands are located above each kidney. Catecholamines may also function as neurotransmitters, important chemical messengers. They regulate the sympathetic nervous system's response to stress.

Calcitonin is produced by the thyroid gland. The hormone plays an important role in lowering blood calcium levels. It is also synthesized as a drug and used in the treatment of hypercalcemia. The other three hormones are indeed secreted by the islets of Langerhans in the pancreas. Insulin, secreted by the beta cells lowers blood sugar, glucagon, secreted by the alpha cells, increases blood sugar, and somatostatin, secreted by the gamma cells regulates digestive and metabolic processes. Lipase is not a hormone, but an enzyme that facilitates the breakdown of lipids. The pancreas does indeed secrete lipase.

The thyroid gland is located (in front) anterior to the trachea. The parathyroid glands are located on the backside on the thyroid. The thyroid is stimulated in response to TSH produced by the anterior pituitary. It will then secrete T3 and T4 although T3 is more potent and produced in a lesser quantity. Calcitonin, a hormone which decreases blood calcium levels, is also produced by the thyroid.

Leptin is secreted by adipose cells, and acts on the arcuate nucleus of the lateral hypothalamus to promote the synthesis of alpha-MSH (alpha-melanocyte-stimulating hormone), which is a hunger suppressant. It also binds to receptors for neuropeptide Y (NPY), a powerful hunger promoter, in the arcuate nucleus. 

None of the other hormones listed, while all involved in nutrient and blood sugar metabolism, directly trigger feeling of satiety.

Leptin, the hormone responsible for feelings of satiety, goes down during times of fasting, with high testosterone, during sleep deprivation, and during periods of prolonged exercise or physical training.

Insulin has many physiological effects on metabolism. It increases uptake of glucose and various ions, especially potassium, from the blood. It promotes glycogen and protein synthesis, and encourages storage of fats. Conversely, insulin inhibits lipolysis, gluconeogenesis, ketogenesis, and proteolysis.