Sex Hormones & Their Relationship with FSH and LH
I. Classification Based on Gender
A. Female Sex Hormones
1. Estrogens
- Natural: Estradiol, Estrone, Estriol
- Synthetic: Ethinyl estradiol, Mestranol, Quinestrol
2. Progestins
- Natural: Progesterone
- Synthetic: Medroxyprogesterone acetate, Norethisterone, Levonorgestrel
B. Male Sex Hormones
1. Androgens
- Natural: Testosterone, Dihydrotestosterone (DHT)
- Synthetic: Methyltestosterone, Fluoxymesterone
2. Anabolic Steroids
- Oxandrolone, Nandrolone
II. Mechanism of Action
Bind to intracellular nuclear receptors, regulate gene transcription, and modulate protein synthesis.
III. Pharmacological Uses
Estrogens & Progestins: Contraception, HRT, menstrual disorders.
Androgens: Male hypogonadism, delayed puberty, anemia, wasting syndromes.
IV. Important Antagonists / Modulators
SERMs: Tamoxifen, Raloxifene - for breast cancer, osteoporosis.
Aromatase Inhibitors: Anastrozole, Letrozole - for estrogen-sensitive cancers.
Antiandrogens: Flutamide, Bicalutamide - for prostate cancer.
5-Alpha Reductase Inhibitors: Finasteride, Dutasteride - for BPH, hair loss.
V. Adverse Effects
Estrogens: Thromboembolism, breast tenderness, endometrial hyperplasia.
Progestins: Weight gain, mood swings, lipid changes.
Androgens: Virilization, liver toxicity, premature epiphyseal closure.
VI. Contraindications
Estrogens: History of DVT, estrogen-sensitive tumors, liver disease.
Androgens: Prostate/breast cancer, liver disease.
Relationship Between Sex Hormones, FSH, and LH
FSH and LH are gonadotropins from the anterior pituitary, regulated by GnRH from the
hypothalamus.
In Females:
- FSH stimulates follicle growth -> estrogen production
- LH triggers ovulation -> corpus luteum -> progesterone
In Males:
- FSH stimulates Sertoli cells -> spermatogenesis
- LH stimulates Leydig cells -> testosterone production
Sex steroids (estrogen, progesterone, testosterone) provide negative feedback to reduce GnRH,
FSH, and LH secretion.
Is Testosterone an Anabolic Steroid?
Yes. Testosterone is a natural anabolic steroid with both androgenic and anabolic effects.
Anabolic: Muscle and bone growth, erythropoiesis.
Androgenic: Male secondary sexual characteristics.
Synthetic anabolic steroids (e.g., Nandrolone, Oxandrolone) are used to enhance anabolic effects
with reduced androgenicity.
Misuse can lead to serious side effects: aggression, liver toxicity, infertility.
