Where are progesterone receptors located in the body?

Progesterone receptors are located in multiple tissues throughout the body. They are primarily found in female reproductive tissues including the uterus (endometrium and myometrium), ovaries, mammary glands, and cervix. However, progesterone receptors are also present in non-reproductive tissues such as the brain (particularly in the hypothalamus), pituitary gland, bone, blood vessels, and immune cells. In men, progesterone receptors exist in the testes, prostate, and brain. These receptors exist in two main forms: progesterone receptor A (PR-A) and progesterone receptor B (PR-B), which have different functions and distributions within tissues. When progesterone binds to these receptors, it activates genomic pathways that regulate gene expression, controlling processes like menstrual cycling, pregnancy maintenance, breast development, and various neurological functions. The widespread distribution of progesterone receptors explains why this hormone influences numerous physiological processes beyond reproduction.