Estradiol (E2)
- Sample Type
- Serum
- Fasting
- No
- Unit
- pg/mL
Function
Estradiol (E2) is the most potent form of estrogen and the primary female sex hormone. In women, it is produced mainly in the ovaries; in men, it is produced in the testes and through the conversion of testosterone in peripheral tissues. It is vital for the growth and development of female reproductive organs and secondary sexual characteristics.
Why it is Ordered
Estradiol testing is used to evaluate ovarian function and assess the cause of menstrual irregularities or infertility. It is also used to monitor follicle development during In Vitro Fertilization (IVF). In men, it may be ordered to investigate feminization (gynecomastia) or to monitor hormonal therapy.
Associated Conditions
- Ovarian Failure: Low levels may indicate menopause or primary ovarian insufficiency.
- Polycystic Ovary Syndrome (PCOS): May involve imbalances in the estradiol-to-estrone ratio.
- Gynecomastia: High levels in men can lead to breast tissue development.
- Precocious Puberty: Early onset of puberty in children.
- Estrogen-secreting Tumors: Both ovarian and testicular tumors can lead to abnormally high levels.
Check Your Result
Check Your Result
Enter your lab result to see where you stand compared to the standard reference range.
Why Context Matters
In females, the 'normal' range for Estradiol shifts significantly depending on the day of the menstrual cycle. A sample taken on day 3 will look vastly different than one taken on day 14. Failure to document the cycle day can lead to gross misinterpretation. Additionally, oral contraceptives, pregnancy, and liver disease can all significantly alter the circulating levels of free estradiol.
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Estradiol (E2):
Official Sources
Research & Guidelines
- PubMed: Estradiol (E2) Clinical GuidelinesNCBI / PubMed
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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