What is estradiol?
Estradiol (E2) is the main estrogen in women of childbearing age who are not pregnant. It is made mostly in the ovaries, helps release an egg each cycle and thickens the lining of the uterus, and supports brain and bone health. Men make small amounts in the testicles.
Estradiol is read in context. MedlinePlus notes that in men estrogen barely changes through life, so a high level usually signals a health problem, while in women it rises at puberty, peaks in pregnancy, falls after menopause and changes day to day through the cycle. That is why one number rarely settles anything, and why doctors pair estradiol with FSH and LH.
Estradiol, estrone and estriol
Blood tests can measure three estrogens. Estradiol (E2) is the one on most hormone panels. Estrone (E1) is the weakest, made mostly by body fat and the adrenal glands, and it is the only estrogen women keep making after menopause. Estriol (E3) is made by the placenta and rises in pregnancy. Make sure your report says estradiol if that is what you meant to test.
Estradiol levels by sex and cycle phase
| Group | pg/mL | pmol/L |
|---|---|---|
| Women, premenopausal | 30 to 400 | 110 to 1,468 |
| Women, postmenopausal | 0 to 30 | 0 to 110 |
| Men | 10 to 50 | 37 to 184 |
Source: MedlinePlus. To convert pg/mL to pmol/L, multiply by 3.671.
Estradiol by cycle phase
ARUP publishes phase-specific ranges for women, measured by immunoassay:
| Cycle phase | pg/mL | pmol/L |
|---|---|---|
| Early follicular (start of cycle) | 22.4 to 115 | 82 to 422 |
| Mid follicular | 25.0 to 115 | 92 to 422 |
| Ovulatory peak | 32.1 to 517 | 118 to 1,898 |
| Mid luteal | 36.5 to 246 | 134 to 903 |
| Postmenopausal | Under 25.1 | Under 92 |
The pmol/L figures are our conversions. ARUP notes that standard immunoassays are not recommended where low levels are expected, such as in men, children and postmenopausal women, and points those groups to a sensitive estradiol test by mass spectrometry. If you are a man or past menopause, check which method your lab used.
ARUP Laboratories cycle-phase ranges (immunoassay); postmenopausal and male ranges from MedlinePlus.
What high estradiol means
In women, high estradiol is normal around ovulation and in pregnancy. Outside those times, MedlinePlus links abnormal results to early puberty and to estrogen-producing tumors of the ovaries. In men, high estradiol can cause breast growth (gynecomastia) and is linked with infertility, erectile dysfunction and testicular or adrenal tumors. Estrogen and some hormone medicines raise results too.
A high result, especially in a man or a postmenopausal woman, is worth taking to your doctor with the rest of your hormone panel.
What low estradiol means
MedlinePlus associates low estradiol with:
- Menopause and perimenopause
- Missing periods (amenorrhea) and reduced ovarian function
- Rapid weight loss or very low body fat
- Genetic conditions such as Turner syndrome
- Pituitary disorders
Low estradiol with high FSH suggests the ovaries are winding down, as at menopause. Low estradiol with low FSH and LH points to the pituitary or hypothalamus, which can follow extreme exercise, stress or very low body weight. See your doctor if your periods stop or become irregular.
Worked example: estradiol and FSH at 47
Say a 47-year-old woman whose periods have become irregular gets an estradiol of 28 pg/mL and an FSH of 38 IU/L on day 3 of her cycle. Her estradiol is near the bottom of ARUP's early follicular range (22.4 to 115 pg/mL) and under MedlinePlus's 30 pg/mL postmenopausal ceiling, and her FSH is inside ARUP's postmenopausal range of 25.8 to 134.8 IU/L.
Low estradiol with high FSH is the pattern this page describes for ovaries that are winding down, as at menopause. But she still has periods, and MedlinePlus says estrogen changes so often that more than one test may be needed to see a trend.
Questions for the doctor: Do these numbers fit perimenopause, given my age and cycles? Should we repeat both on the same cycle day next month? Which of my symptoms are worth treating, and what are the options? Our perimenopause blood test guide covers which markers help.
What can change estradiol
- Cycle day. The biggest factor in premenopausal women. Always note the day.
- Medicines. MedlinePlus lists birth control pills, estrogen, testosterone, DHEA, corticosteroids, some antibiotics (ampicillin, tetracycline) and phenothiazines. Do not stop any medicine before testing unless your doctor says so.
- Body fat and weight change. Rapid weight loss and very low body fat lower estradiol.
- Testosterone is on MedlinePlus's list of medicines that can affect estradiol results, which matters for men on testosterone therapy.
How to test estradiol
- If you have periods, record the first day of your last period, and test on the cycle day your doctor asks for.
- Men and postmenopausal women should use a sensitive (mass spectrometry) assay.
- Tell whoever orders the test about any hormones, birth control or supplements.
- Expect to need more than one test to see a trend, as MedlinePlus advises.
Common questions about estradiol
Why would a man test estradiol?
MedlinePlus lists late puberty, breast growth (gynecomastia), infertility and erectile dysfunction as reasons to check estrogen in males. Men on testosterone therapy also track it, since testosterone is on MedlinePlus's list of medicines that change estradiol results. Ask for a sensitive (mass spectrometry) test, and read it with total testosterone and SHBG.
Should I stop birth control before testing?
MedlinePlus says you may need to stop birth control pills or menopause hormone therapy before an estrogen test, but only your doctor can say whether, and for how long. If you stay on them, record it next to the result, because both change estradiol.
What else is estradiol used to monitor?
MedlinePlus lists infertility treatment and menopause hormone therapy. In both cases the trend across repeat tests matters more than any single value.
Which at-home tests include estradiol
SiPhox Health measures sensitive estradiol on four panels. Longevity Essentials includes it for women only, alongside FSH, LH and the LH:FSH ratio. Hormone Focus includes it for both sexes with progesterone, prolactin, testosterone and SHBG. Ultimate 360 and GLP Optimization include it too. Men who want estradiol need Hormone Focus, Ultimate 360 or GLP Optimization. For a full women's panel, compare options in our at-home hormone test guide for women.
A note on home samples: SiPhox's partner lab tests capillary blood collected from the upper arm. SiPhox says its results show a 95% to 99% correlation with venous draws in its own quarterly comparisons against Labcorp and Quest, but it has not published a study of the EasyDraw device. If a result would change a treatment decision, confirm it with a venous test through your doctor.
Hormone Focus
Sex hormones for men and women, including PSA for men and progesterone for women.
Check price
Longevity Essentials
The default panel: heart, metabolic, hormone and inflammation markers in one draw.
Check price
Ultimate 360
Everything on the four core panels plus iron studies, B12 and folate, GGT and PSA.
Check priceFrequently asked questions
What is a normal estradiol level for a woman?
About 30 to 400 pg/mL before menopause, varying with cycle phase, and 0 to 30 pg/mL after menopause (MedlinePlus). ARUP's ovulatory peak range reaches 517 pg/mL.
What is a normal estradiol level for a man?
About 10 to 50 pg/mL (37 to 184 pmol/L) according to MedlinePlus. Use a sensitive mass spectrometry test, since standard immunoassays are less reliable at low levels.
What estradiol level indicates menopause?
Postmenopausal estradiol is usually under 30 pg/mL (MedlinePlus) or under 25.1 pg/mL on ARUP's assay. A single estradiol result cannot confirm menopause on its own; your doctor will consider your periods, symptoms and often FSH.
What day of the cycle should estradiol be tested?
It depends on the question, so follow your doctor's timing. Levels are lowest early in the cycle and peak before ovulation, so always record your cycle day.
Sources
- MedlinePlus Medical Encyclopedia: Estradiol blood test
- MedlinePlus Lab Tests: Estrogen levels test
- ARUP Laboratories Test Directory: Estradiol (adult premenopausal females)
- ARUP Laboratories Test Directory: Luteinizing hormone and follicle stimulating hormone
- SiPhox Health: panel comparison (checked 29 Sep 2026)
- SiPhox Health: Longevity Essentials panel
- SiPhox Health: Hormone Focus panel