Estradiol (E2)
Estradiol is the most potent and abundant estrogen. In women, it regulates the menstrual cycle, bone density, and cardiovascular health. In men, optimal levels support bone health and libido.
Levels vary dramatically with menstrual cycle phase and age.
What It Measures
Serum estradiol concentration.
Reference Ranges
| Status | Range (pg/mL) |
|---|---|
| Optimal | Women (follicular): 30–100 pg/mL. Men: 20–40 pg/mL |
| Normal | Phase-dependent |
| Borderline | Context-dependent |
| Out of Range | Context-dependent |
Range by Cycle Phase
| Cycle Phase | Reference Range |
|---|---|
| Follicular | 30–120 pg/mL (days 1–13) |
| Ovulatory | 100–400 pg/mL (days 14–16, peak) |
| Luteal | 50–250 pg/mL (days 17–28) |
| Menopause | < 30 pg/mL |
Source: Endocrine Society, ACOG. Ranges are approximate — consult your provider.
When to test: Any day for general check. Day 3 for baseline fertility assessment.
Interpreting Your Results
When Values Are High
May indicate ovarian cysts, estrogen-producing tumors, liver disease, or obesity (aromatase activity). In men, high estradiol causes gynecomastia.
When Values Are Low
May indicate menopause, premature ovarian insufficiency, hypothalamic amenorrhea, or low body fat. Symptoms: hot flashes, bone loss, vaginal dryness.
How GATOR Tracks This
Lab Providers
Related Biomarkers
This content is for informational purposes only and does not constitute medical advice. Reference ranges may vary by laboratory and individual factors. Consult a qualified healthcare provider for interpretation of your results and treatment decisions.
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