Estradiol (E2) and Estrogen Tests
Definition
Three main types of estrogen can be measured:
| Type | Description |
|---|---|
| Estradiol (E2) | The main estrogen in non-pregnant women of reproductive age. Produced mainly in the ovaries. Men produce small amounts in the testicles |
| Estrone (E1) | The weakest form; produced by body fat and the adrenal glands. The only type of estrogen that women continue to produce after menopause |
| Estriol (E3) | Rises during pregnancy, produced in the placenta. Very low in men and non-pregnant women |
Purpose
- In women: Puberty disorders, PCOS, thyroid disease, infertility, ovarian tumors, diagnosis of perimenopause; monitoring of hormone therapy or fertility treatment
- In pregnancy: Screening for birth defects such as Down syndrome, or monitoring high-risk pregnancies
- In men: Delayed puberty, gynecomastia, infertility, erectile dysfunction, or estrogen excess leading to testicular/adrenal cancers
Results
Results vary markedly by age, sex and the purpose of testing.
Normal Values
Laboratory-specific and cycle-phase-specific.
Risks and Limitations
Because estrogen levels change very frequently, you may need to be tested more than once; seeing the trend is more meaningful than a single measurement.