<unk>  (P4) is an endogenous steroid and<unk> estogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the<unk> estogens and is the major<unk> estogen in the body.<unk>  has a variety of important functions in the body. It is also a crucial metabolic intermediate in the<unk> duction of other endogenous steroids, including the sex hormones and the corticosteroids, and plays an important role in brain function as a neurosteroid. In addition to its role as a natural hormone,<unk>  is also used as a medication, such as in combination with estrogen for contraception, to reduce the risk of uterine or cervical cancer, in hormone replacement therapy, and in feminizing hormone therapy. It was first prescribed in 1934.
Progesterone
Estrogen 
Estrogen
Androgen
Estradiol 
Estradiol
Methyltestosterone
Progestogen