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Hormone health

Estradiol

Also known as: E2 test, Serum estradiol, Estrogen test (estradiol fraction)

Estradiol (E2) is the most potent form of estrogen, the hormone that regulates many aspects of female health, including the menstrual cycle, cardiovascular system, skeletal system, and neurologic system, among others. The ovaries are the primary producers of the body’s estradiol before menopause. The adrenal glands and fat tissue produce less significant quantities of the hormone.  

An estradiol test measures the amount of the hormone present in your blood. Results can help evaluate irregular menstrual cycles, fertility issues, the transition to menopause, and the efficacy of hormone therapy.

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Key takeaways

  • Sample required: Blood

  • Tests for: Estradiol, the most potent form of estrogen that’s synthesized by the ovaries; lab results provide insights into ovarian function, fertility, hormone therapy monitoring, and whether the body is preparing for menopause

  • Healthy range: Normal estradiol levels for women of reproductive age typically range from about 30 to 350 picograms per milliliter (pg/mL), and levels in women who are postmenopause are usually less than 30 pg/mL

What can an estradiol test tell you?

Estradiol testing helps healthcare providers understand ovarian and hormonal function. The results may have various applications for understanding and treating central components of women’s health. Such use cases include the ability to: 

What is being tested?

Estradiol is a steroid hormone in the estrogen family. It plays a central role in developing the reproductive organs and secondary sex characteristics; regulating the menstrual cycle; and maintaining bone, brain, cardiovascular, and skin health.

Levels of estradiol naturally fluctuate. Here’s when they shift, and in which direction:

  • Follicular phase. Lower at the start of the menstrual cycle.

  • Pre-ovulation. Sharp rise before ovulation.

  • Luteal phase. Drop if fertilization doesn’t occur.

  • Pregnancy. A time of higher levels due to placental production.

  • Postmenopause. Dramatic decrease, with ovarian estradiol production nearly absent.

Because estradiol levels naturally shift for various reasons, a provider will consider your specific biomarkers and stage of life when ordering the lab work and interpreting the results.

Where is the estradiol test typically included?

Estradiol is not usually part of standard metabolic panels like the basic metabolic panel (BMP) and comprehensive metabolic panel (CMP). Instead, a provider will order it as a single test or alongside other reproductive hormone labs, such as:

  • Follicle-stimulating hormone (FSH)

  • Luteinizing hormone (LH)

  • Progesterone

  • Anti-Müllerian hormone (AMH)

These tests may be bundled in more comprehensive fertility or menopause evaluation panels.

Who should get an estradiol test?

You and your provider may decide estradiol testing is appropriate if you:

  • Have menstrual irregularities. Such irregularities include missed periods, irregular cycles, or very heavy bleeding.

  • Experience infertility. Estradiol test results alongside FSH and LH may help clarify ovulatory issues. 

  • Are approaching menopause. Signs of perimenopause and menopause may include experiencing hot flashes, night sweats, or other symptoms.

  • Have suspected PCOS or ovarian insufficiency. These are conditions that alter estrogen balance.

  • Are on hormone therapy. Estradiol levels can help gauge the effectiveness and safety of treatment.

  • Show early or delayed puberty. Testing can help track developmental progress.

  • Are being evaluated for possible estrogen-secreting tumors. Unusually high estradiol levels outside expected ranges may raise suspicion.

How Labs by Hers works

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Not available in all 50 states. Eligibility and provider order required. Lab results alone are not intended to diagnose, treat, or cure any condition. A provider will reach out about critical results and plans include access to 24/7 provider messaging.

Images for illustrative purposes only.

Frequently asked questions

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What causes changes in estradiol levels?

Estradiol levels in women can fluctuate due to health conditions, certain medications, or lifestyle factors. 

Factors that could contribute to increased estradiol levels include certain hormonal medications, higher body fat percentage, alcohol consumption, liver dysfunction, and stress. 

Factors that could contribute to decreased estradiol levels include low body fat, extreme weight loss, physical or emotional stress, restrictive diets, overexercise, smoking, chronic illness, inflammation, or certain medications.

What is the normal reference range for estradiol in females?

Normal estradiol levels for women of reproductive age typically range from about 30 to 350 pg/mL, and levels in women who are postmenopause are usually less than 30 pg/mL.

Estradiol levels can also fluctuate based on your menstrual cycle:

• Follicular phase. 30-144 pg/mL.

• Mid-cycle. 64-357 pg/mL.

• Luteal phase. 56-214 pg/mL.

When is the best time in the cycle to test estradiol?

Estradiol is often checked early in the menstrual cycle (day three) for fertility or ovarian reserve testing.

Do I need to fast before an estradiol test?

Fasting is generally not required before an estradiol test, but you should always check in with your healthcare provider for special instructions.

Can I test my estradiol levels at home?

Yes, some at-home testing kits allow you to test your estradiol from home. 

How do estradiol levels change after menopause?

After menopause, levels drop significantly, often below 30 pg/mL, due to reduced ovarian function. The typical range for women of reproductive age is 10 to 300 pg/mL.

What tests are related to this biomarker?

• Follicle-stimulating hormone

• Luteinizing hormone

• Progesterone

• Anti-Müllerian hormone

• Thyroid function tests

The information provided here is for informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk to a qualified healthcare provider about your specific health concerns.

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Reviewed by Felix Gussone, MD

Published 12/04/2025