What Is Oestradiol?
Oestradiol (E2) is the most potent form of oestrogen in reproductive-age women, produced mainly by the ovarian follicles. It plays a central role in the menstrual cycle, bone density, heart health and sexual development.
Normal Oestradiol Levels
| Phase / Group | Normal Range |
|---|---|
| Follicular phase | 30–120 pg/mL |
| Mid-cycle peak (ovulation surge) | 100–500 pg/mL |
| Luteal phase | 60–260 pg/mL |
| Post-menopause | < 20–30 pg/mL |
| Males (adults) | 8–35 pg/mL |
Causes of Low Oestradiol
- Premature ovarian insufficiency (early menopause)
- PCOS (some subtypes)
- Hypothalamic amenorrhoea (excessive exercise, low body weight, stress)
- Hyperprolactinaemia — prolactin suppresses oestrogen
- Post-menopause
Causes of High Oestradiol
- Ovarian cysts or tumours
- Obesity (fat tissue converts androgens to oestrogen)
- Liver disease (impaired oestrogen metabolism)
- Fertility medications (FSH injections)
- In men: gynaecomastia (breast tissue growth)
Oestradiol and Bone Health
Low oestrogen after menopause leads to accelerated bone loss. Measuring oestradiol helps guide decisions about hormone replacement therapy (HRT) for bone protection.
FAQs
When should oestradiol be tested?
For fertility assessment: ideally on day 2–4 of your menstrual cycle (early follicular phase).
Does oestradiol affect mood?
Yes — oestrogen influences serotonin receptors. Low levels are linked to depression, anxiety and brain fog, particularly around menopause.
Can men have oestradiol tested?
Yes — elevated oestradiol in men can cause gynaecomastia, reduced libido and infertility.
Medical Disclaimer: Oestradiol levels change throughout the menstrual cycle. Results must be interpreted alongside the day of cycle and clinical findings by your doctor.