📅 Last Updated: April 2026 | 🩺 Medically Reviewed by: Edward Salko, D.O., Medical Director | 🧪 Lab Partner: Labcorp
Also Known As
E2 Test, Estradiol E2 Blood Test, Estrogen Blood Test
What Is an Estradiol Blood Test?
An estradiol blood test measures the level of estradiol (E2) — the most potent and predominant form of estrogen — circulating in your bloodstream. Estradiol is produced primarily by the ovaries in women and in smaller amounts by the testes in men and by adrenal glands in both sexes.
Estradiol plays a central role in female reproductive health, bone density, cardiovascular function, mood regulation, and brain health. Testing estradiol levels helps evaluate fertility, diagnose hormonal imbalances, monitor menopause, and guide hormone replacement therapy. According to the Endocrine Society, estradiol is one of the most clinically important hormones to measure across all stages of reproductive life.
What Does the Estradiol Test Measure?
This test measures total estradiol concentration in your blood serum. Estradiol (E2) is one of three main estrogens — alongside estrone (E1) and estriol (E3) — but it is by far the most biologically active during reproductive years. In women, levels fluctuate significantly across the menstrual cycle and drop sharply at menopause. In men, estradiol regulates libido, erectile function, and bone health, and elevated levels can signal issues with testosterone metabolism.
Estradiol Normal Reference Ranges
| Group | Estradiol Level (pg/mL) | Notes |
|---|---|---|
| Women — Follicular Phase | 19–144 | Early in menstrual cycle |
| Women — Midcycle Peak | 64–357 | Around ovulation |
| Women — Luteal Phase | 56–214 | Post-ovulation |
| Women — Postmenopausal | < 32 | Naturally low after menopause |
| Men | 10–40 | Baseline normal range |
| Prepubertal children | < 15 | Before puberty |
Reference ranges may vary slightly by laboratory. Results should always be interpreted in the context of symptoms, cycle timing, and clinical history.
What Can Estradiol Levels Reveal?
Low estradiol may indicate:
- Primary ovarian insufficiency (premature ovarian failure)
- Menopause or perimenopause
- Hypothalamic amenorrhea (from stress, excessive exercise, or low body weight)
- Hypopituitarism
- Turner syndrome
- Low bone density risk
High estradiol may indicate:
- Ovarian cysts or tumors
- Gynecomastia in men (breast tissue enlargement)
- Early puberty in children
- Liver disease (impairs estrogen metabolism)
- Obesity (fat tissue converts androgens to estradiol)
- Estrogen-secreting adrenal tumors
- Over-supplementation with estrogen or testosterone therapy
What Is the Estradiol Test Used For?
The estradiol test is ordered for a wide range of clinical purposes:
Fertility evaluation: Estradiol on cycle day 3 is a key marker in ovarian reserve testing. Low E2 combined with high FSH suggests diminished ovarian reserve. During IVF cycles, serial estradiol measurements track follicle development.
Menopause assessment: Rising FSH and falling estradiol confirm the transition to menopause. Testing helps determine whether symptoms like hot flashes, night sweats, and vaginal dryness are estrogen-related.
Hormone replacement therapy (HRT) monitoring: Women on estrogen therapy use estradiol testing to confirm adequate levels and avoid over- or under-dosing.
Irregular periods: Low or fluctuating estradiol is a common cause of missed or irregular menstrual cycles.
Bone health: Estradiol is critical for bone density. Postmenopausal women and those with low E2 at any age are at higher risk for osteoporosis.
Male hormone evaluation: Men with symptoms of low testosterone, gynecomastia, or sexual dysfunction may have elevated estradiol from excess aromatization of testosterone.
Puberty disorders: Early or delayed puberty in children often involves abnormal estradiol levels.
When to Test Estradiol — and Why Timing Matters
Estradiol is the primary form of estrogen in women of reproductive age — and unlike most blood tests, when you test matters enormously.
Day 3 testing (fertility evaluation) — testing estradiol on cycle day 3 alongside FSH gives the most accurate picture of ovarian reserve and egg quality. Day 3 estradiol above 80 pg/mL is associated with reduced ovarian reserve and poorer IVF outcomes even if FSH appears normal. This is why fertility specialists always test both.
Mid-cycle testing (ovulation confirmation) — estradiol peaks 24-36 hours before ovulation, reaching 200-400 pg/mL. Testing at this time confirms the ovulatory surge occurred.
Perimenopause monitoring — erratic estradiol fluctuations are the defining characteristic of perimenopause. Estradiol may swing from very high to very low in the same cycle. Serial testing every 3-6 months tracks the transition.
HRT monitoring — women on hormone replacement therapy should test estradiol every 3-6 months to confirm therapeutic levels and adjust dosing. Target range on HRT is typically 50-200 pg/mL depending on the form and route of administration.
Men on TRT — estradiol must be monitored in men on testosterone therapy. Testosterone aromatizes to estradiol, and levels above 40-50 pg/mL cause water retention, mood changes, and erectile dysfunction. Target range on TRT is 20-40 pg/mL.
Reviewed by Edward Salko, D.O., Medical Director, Personalabs
Who Should Get an Estradiol Test?
- Women experiencing irregular, missed, or painful periods
- Women trying to conceive or undergoing fertility treatment
- Women approaching or experiencing menopause symptoms (hot flashes, mood changes, night sweats, vaginal dryness)
- Women on hormone replacement therapy
- Women with known or suspected polycystic ovary syndrome (PCOS)
- Women with unexplained bone loss or osteoporosis at a young age
- Men with gynecomastia (enlarged breast tissue), low libido, or erectile dysfunction
- Men on testosterone replacement therapy
- Anyone with a suspected estrogen-secreting tumor
- People with unexplained fatigue, mood swings, or brain fog related to hormonal changes
Test Preparation
No fasting required. You can eat and drink normally before this test.
Timing matters for women: Estradiol fluctuates throughout your menstrual cycle. For fertility workups, providers typically order this test on cycle day 3 (three days after the start of your period). For other purposes, your provider or your own tracking can guide the best timing. If you’re unsure, morning testing is generally preferred since hormone levels tend to be more stable.
Medications to note: Oral contraceptives, hormone replacement therapy, fertility drugs, and certain antidepressants can all affect estradiol levels. Note any relevant medications when reviewing your results.
How Much Does an Estradiol Test Cost?
| Where You Get Tested | Typical Cost | Notes |
|---|---|---|
| Personalabs | $49–$79 | Physician order included |
| OB-GYN office visit + lab | $200–$400+ | Office copay + lab fees |
| Fertility clinic | $300–$600+ | Facility and processing fees |
| Hospital outpatient lab | $300–$700+ | Facility fees apply |
HSA and FSA eligible. Estradiol testing qualifies as a reimbursable medical expense.
How to Order Your Estradiol Test
Step 1: Order online — your physician-approved lab order is ready within 2–4 hours. Step 2: Find a lab near you using our Lab Locator. Step 3: Walk in for your blood draw — no fasting needed. Step 4: Get results in your secure Personalabs account within 24–48 hours.
Frequently Asked Questions: Estradiol Blood Test
What is a normal estradiol level for women?
Normal estradiol ranges vary by phase of the menstrual cycle. Day 3 baseline should be below 80 pg/mL. Follicular phase 19 to 144 pg/mL. Mid-cycle ovulatory peak 64 to 357 pg/mL. Luteal phase 56 to 214 pg/mL. Post-menopausal below 30 pg/mL. For fertility evaluation, day 3 testing alongside FSH gives the most clinically useful information.
When should I test estradiol for fertility purposes?
Test estradiol on day 3 of your menstrual cycle — day 1 being the first day of full flow. Day 3 estradiol above 80 pg/mL is associated with reduced ovarian reserve even when FSH appears normal. Day 3 testing alongside FSH and AMH gives the most complete fertility picture. Available through Personalabs without a doctor’s visit.
What are symptoms of low estradiol?
Low estradiol causes hot flashes, night sweats, vaginal dryness, mood changes, brain fog, poor sleep, reduced bone density, and joint pain. These are the hallmark symptoms of perimenopause and menopause. Low estradiol in younger women may indicate premature ovarian insufficiency or hypothalamic dysfunction.
Why do men need to test estradiol?
Men produce small amounts of estradiol from testosterone conversion. Men on TRT need regular estradiol monitoring because testosterone aromatizes to estradiol — levels above 40-50 pg/mL cause water retention, gynecomastia, mood changes, and erectile dysfunction. The target range for men on TRT is typically 20 to 40 pg/mL.
Do I need to fast for an estradiol blood test?
No fasting required. However timing matters — test on a specific cycle day for meaningful results. Day 3 of your cycle for fertility evaluation. Anytime for perimenopause or menopause assessment. Available through Personalabs without a doctor’s visit — results in 24 to 48 hours.
