Female hormone physiology Other related pages




Female hormones
Hormone Reproductive age Menopause
Estradiol (E2)
  • Primary hormone secreted by the follicle in the ovaries
  • 12 - 80 times more potent than estrone and estriol
  • Stimulates development of the female sex organs during puberty
  • Stimulates thickening of the endometrium during the menstrual cycle
  • Levels range from 12.5 - 498 pg/ml depending on the phase of the menstrual cycle
  • Ovarian estradiol production ceases
  • A small amount is produced by the conversion of adrenal steroids in peripheral fat tissue
  • Levels range from 0 - 55 pg/ml depending on the length of menopause
Estrone (E1)
  • Not as potent or abundant as estradiol
  • Levels range from 37 - 229 pg/ml depending on the phase of the menstrual cycle
  • After estradiol levels fall, estrone becomes the predominant estrogen
  • Primarily formed from peripheral aromatization of androstenedione in the adrenal gland
  • Levels range from 14 - 103 pg/ml depending on the length of menopause
Estriol (E3)
  • Main pregnancy estrogen
  • Synthesized in the placenta
  • Has no significant role outside of pregnancy
  • No significant role
Progesterone
  • Produced by the corpus luteum in the ovaries
  • Causes the endometrium to become secretory, preparing it for ovum implantation
  • Produced by the placenta during the second and third trimesters
  • Progesterone levels measured 1 week prior to expected menses (cycle day 21) can be used to assess ovulation. Typically a level > 3 ng/ml indicates ovulation.
  • Levels range from 0.2 - 27 ng/ml depending on the phase of the menstrual cycle
  • Ovarian progesterone production stops
  • Levels range from 0.1 - 0.8 ng/ml
Follicle-Stimulating
Hormone (FSH)
  • FSH is released from the anterior pituitary in response to GnRH
  • FSH stimulates follicles in the ovary to mature
  • Levels range from 3.5 - 21.5 mIU/ml depending on the phase of the menstrual cycle
  • Loss of negative feedback from estrogen leads to high levels
  • Levels range from 25.8 - 135 mIU/ml
Luteinizing
Hormone (LH)
  • LH is released from the anterior pituitary in response to GnRH
  • The LH surge in the middle of the menstrual cycle stimulates ovulation
  • LH maintains the corpus luteum and stimulates steroid production
  • Levels range from 2.4 - 95.6 mIU/ml depending on the phase of the menstrual cycle
  • Loss of negative feedback from estrogen leads to higher levels
  • Levels range from 7.7 - 58.5 mIU/ml
Testosterone
  • Produced by the ovaries in small amounts
  • Aromatase converts testosterone to estradiol in the ovaries
  • Levels range from 8 - 48 ng/dl
  • Ovaries continue to produce testosterone
  • Levels range from 3 - 41 ng/dl














Drug Mechanism Dosing Other
Clomiphene

(Clomid®)
  • Clomiphene is a selective estrogen receptor modulator (SERM). See SERM activity table for more).
  • Clomiphene blocks estrogen receptors in the hypothalamus (and possibly the pituitary) which decreases the negative feedback of estradiol and increases GnRH release (see HPO axis above).
  • Increased GnRH release stimulates FSH release which in turn, stimulates ovarian follicular development
  • Starting: 50 mg once daily for 5 days starting on the 5th day of the cycle
  • Dose may be increased to 100 mg/day in subsequent cycles
  • In studies, doses up to 150 mg/day have been used
  • For women with no recent menstruation, therapy may be started at any time
  • Only 3 cycles are recommended, but been used for up to 6 cycles in some studies.
  • Dosage form: 50 mg tablet
  • Generic: - yes/$ (30 tablets)
  • May cause visual blurring or other visual symptoms such as spots or flashes
  • May cause abdominal bloating, breast pain, and hot flashes
  • Ovarian hyperstimulation syndrome may occur. Symptoms include abdominal or pelvic pain, weight gain, discomfort, and distention.
  • Increases chance of multiple pregnancies (6 - 9% depending on the study and patient population)
  • Use lower dose in PCOS
Letrozole

(Femara®)
  • In the ovaries, the aromatase enzyme converts testosterone and androstenedione to estradiol
  • Letrozole inhibits aromatase and decreases estradiol levels
  • With decreasing estradiol levels, negative feedback on the pituitary is diminished, and FSH production is increased (see HPO axis above)
  • FSH stimulates ovarian follicular development
  • Dosing: 2.5 - 5 mg once daily for 5 days starting on Day 3 - 5 of the menstrual cycle
  • Doses up to 7.5 mg/day have been used in studies
  • Use in infertility is off-label
  • Has been used for up to 5 cycles in studies
  • Dosage form: 2.5 mg tablet
  • Generic: - yes/$ (30 tablets)
  • May cause fatigue, dizziness, and somnolence
  • May cause abdominal bloating, breast pain, and hot flashes
  • Ovarian hyperstimulation syndrome may occur. Symptoms include abdominal or pelvic pain, weight gain, discomfort, and distention.
  • Increases chance of multiple pregnancies (3 - 13% depending on the study and patient population)
Gonadotropins

(Gonal-f®)
(Menopur®)
  • Gonadotropins (FSH and LH) are available in several injectable preparations
  • FSH stimulates follicular development (see HPO axis above)
  • Gonal-f is FSH made from recombinant DNA
  • Menopur is 1:1 mixture of FSH and LH. Menopur is extracted from the urine of postmenopausal women.
  • Gonadotropin is injected daily starting on Day 3 - 5 of the menstrual cycle
  • Ovarian response is monitored by ultrasound
  • Once appropriate follicular response is observed, hCG is injected to stimulate ovulation
  • Injections are very expensive
  • May cause abdominal bloating and breast pain
  • Ovarian hyperstimulation syndrome may occur. Symptoms include abdominal or pelvic pain, weight gain, discomfort, and distention.
  • Increases chance of multiple pregnancies (up to 32% depending on the study and patient population)