Estrogen is a female sex hormone that is produced in the ovaries and, to a lesser degree, in the adrenal glands and adipose tissues. It is essential for the development of primary and secondary sex characteristics, as well as function of the reproductive organs. Estrogen also plays a role in several other processes, including bone metabolism and liver function. While ovarian insufficiency, aromatase deficiency, and hyperprolactinemia result in pathologically low estrogen levels, a decrease in estrogen is a normal feature of menopause. Possible clinical features of estrogen deficiency include menopausal symptoms, vaginal and endometrial atrophy, and osteoporosis. Increased estrogen levels may also have adverse effects, including gynecomastia, thrombosis, and an increased risk of breast and endometrial cancer. Progesterone is a female sex hormone produced by the corpus luteum in nonpregnant women and, in pregnant women, by the corpus luteum graviditatis until the 10th week of gestation, after which the placenta takes over production. Progesterone plays an important role in the preparation of the endometrium for implantation of a fertilized ovum and maintenance of pregnancy. Synthetic progesterone derivatives are called “progestins” and are used as contraceptives and are used in the treatment of conditions resulting from endometrial proliferation (e.g., endometriosis, endometrial cancer).
|Overview of female sex hormones|
|Effects in uterus|
|Effects in cervix|| |
|Effects in other tissues|
|Effects of hyperproduction|| |
|Effects of hypoproduction|
Ovarian estrogen synthesis
- LH stimulates androgen synthesis in ovarian theca cells.
- FSH stimulates conversion of androgens to estrogens.
- Conversion of androgens to estrogens is catalyzed by the aromatase enzyme.
Extra-ovarian estrogen synthesis 
- Potency: estradiol > estrone > estriol
- During pregnancy, estrogen concentration increases.
- When estrogen binds to its receptor in the cytoplasm, a hormone-receptor complex is formed that translocates to the nucleus.
Measurement of unconjugated estriol (uE3 or free estriol) is part of the prenatal screening for fetal anomalies (i.e., triple screen test and quad screen test). Decreased levels are associated with Down syndrome, Edward syndrome, molar pregnancy, and fetal demise.
- Cervix 
- Vagina: proliferation of epithelium
- Pubis: hair growth
- Breast: breast growth
Extragenital tissue 
- Bones: ↑ bone formation by inhibiting bone resorption (induces osteoclast apoptosis)
- Blood vessels: protective effect against atherosclerosis
- Blood clotting: ↑ risk of thrombosis
- Kidneys: ↑ water and sodium retention (may contribute to edema)
- Protein synthesis
- Adipose tissue: female distribution of adipose tissue
- ↑ Cancer risk
- Spider nevi, gynecomastia, and testicular atrophy in individuals with cirrhosis
- Breast hypertrophy, gynecomastia (in men), galactorrhea
- Weight gain (edema)
- Liver toxicity 
- Nausea and vomiting
- Depressive moods
- Definition: a condition of increased circulating estrogen
- Both sexes: palmar erythema, spider telangiectasias
- Menstrual irregularities (see "The menstrual cycle and menstrual cycle abnormalities")
- Enlargement of the breast and uterus
- ↑ Cancer risk (e.g., endometrial cancer)
- Definition: a condition of decreased circulating estrogen
- Clinical features
- In nonpregnant women: granulosa cells of the corpus luteum
- In pregnant women
- The effects of progesterone are mediated via intracellular receptors.
- For the effects of progesterone in pregnancy, see “Placental function” in "The placenta, umbilical cord, and amniotic sac.”
- Cervix: ↓ cervical mucus production → cervical mucus thickening (inhibits entry of spermatozoids to the uterus)
- Breasts: inhibits prolactin (the decrease in progesterone levels after delivery disinhibits prolactin, triggering lactation)
Role in menstrual cycle
- After ovulation, the ruptured follicle transforms into the corpus luteum, which produces progesterone.
- Progesterone induces changes in internal reproductive organs required for proper implantation of a zygote and inhibits the secretion of FSH and LH, preventing other follicles from developing.
- See "The menstrual cycle and menstrual cycle abnormalities."
- Associated pathologies: low levels of progesterone are associated with infertility, premature birth, and spontaneous abortion 
- Synthetic progesterone derivatives (progestins) are indicated for the following conditions:
- See “Reproductive system drugs” in “General endocrinology” for more information about the pharmacology of progestins.
Reproductive system drugs
|Overview of reproductive system drugs|
|Drug class||Examples||Mechanism of action||Indications||Side effects|
|Selective estrogen receptor modulators (SERMs)|| |
| || |
|Synthetic estrogens || |
|Aromatase inhibitors|| |
|Anabolic steroids || |
|Progestins || |
|Antiprogestins || || |
- See “.”