What is this test?
Estradiol is a major estrogen. It is involved in the menstrual cycle, ovulation, bone health and reproductive function in both sexes.
Why might it be ordered?
- For cycle disorders, signs of early or late puberty, or difficulty getting pregnant.
- To monitor ovarian function, pregnancy or hormone treatment when prescribed.
What sample is needed?
A healthcare professional collects a venous blood sample. Depending on the method, the laboratory uses serum or plasma.
How should you prepare?
For women, the cycle day and pregnancy status matter for interpretation. Report oral contraceptives and other hormone treatment. Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
The value varies greatly with age, sex, cycle day, pregnancy and treatment, and is often interpreted with FSH and LH. Your result is interpreted using the reference interval on the laboratory report and in the context of your symptoms, medical history and other test findings.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.