The posterior pituitary gland is not a 'true' endocrine gland...

The posterior pituitary gland is not a true endocrine gland because it only stores and releases hormones. The posterior lobe contains the ends of nerve cells coming from the hypothalamus. The hypothalamus sends hormones directly to the posterior lobe via these nerves, and then the pituitary gland releases them.

Antidiuretic hormone (ADH) or Vasopressin: This hormone prompts the kidneys to increase water absorption in the blood.

Oxytocin is involved in a variety of processes, such as contracting the uterus during childbirth and stimulating breast milk production.