Hormone Panel Updated Apr 17, 2026

Estradiol (E2)

Estradiol (E2) is the main form of estrogen measured in blood, and an Estradiol test reports how much E2 is circulating at the time of collection. E2 on a lab report is commonly used in hormone panels to track normal variation across sex, age, and treatment patterns.

What Is Estradiol (E2)?

Estradiol (E2) is a blood hormone value that measures the amount of estradiol circulating at the time of the blood draw. E2 is the most studied form of estrogen in routine lab reporting, and Estradiol on a blood test reflects current hormone activity rather than a long-term average. It is commonly listed as Estradiol on a lab report in hormone-focused testing. The Estradiol test result is usually interpreted in the context of sex, age, and other hormone values.

Why Is Estradiol (E2) Tested?

The E2 test is most often ordered in hormone panels, fertility-related panels, and other reproductive hormone workups. Estradiol on a lab report helps show how much estrogen activity is present at the time of testing, which adds context to cycles, treatment monitoring, and general hormone balance. Estradiol on a blood test is usually reviewed with other hormones rather than alone. It is not part of a CBC or CMP, but it is commonly paired with other hormone measurements in the same draw.

Already have your Estradiol results?

Upload your blood test to BloodSight and see what each result means in context.

Get Started

Estradiol (E2) Normal Range

Group Range Unit
Adult Male 10–40 pg/mL
Adult Female 15–350 pg/mL

Reference ranges may vary by laboratory and individual factors.

What Does High E2 Mean?

A high E2 result generally means more estradiol is circulating than expected for the reference group. In simple terms, the Estradiol test result suggests stronger estrogen activity at the time of collection, often from increased hormone production or reduced clearance. A high E2 is often considered above about 350 pg/mL in many adult male reference systems, while adult female values vary widely by cycle stage. On a lab report, high E2 is best read as a snapshot of current hormone state, not a permanent trait.

Associated factors

Pregnancy — E2 production rises substantially as hormone output increases.
Menstrual-cycle phase — E2 can peak during the mid-cycle window and vary across the month.
Estrogen-containing medications — added estrogen directly raises measured E2.
Hormone therapy — treatment with estrogen can produce a high E2.
Lower body fat change with redistribution — altered hormone storage and conversion can influence circulating E2.
Alcohol use — may affect hormone metabolism and shift E2 upward in some settings.
Liver clearance changes — slower breakdown can leave more E2 in circulation.
Lab timing — different collection times can capture a natural peak and look like high E2.

What Does Low E2 Mean?

A low E2 result generally means less estradiol is circulating than expected for the reference group. The Estradiol test result may reflect reduced hormone production, lower conversion to estradiol, or faster clearance from blood. A low E2 is often considered below about 10 pg/mL in adult female reference systems outside of hormone peaks, while adult male values are usually lower overall. On a lab report, low E2 is a measurement snapshot and can shift with age, medications, and timing.

Associated factors

Natural age-related decline — hormone output can fall over time and lower E2.
Postpartum state — hormone levels can drop after pregnancy-related hormone changes.
Low body fat — less hormone storage and conversion can contribute to low E2.
High training load — intense exercise can shift hormone balance toward low E2.
Low caloric intake — limited energy availability can reduce hormone production.
Medications that block estrogen action or production — these can lower measured E2.
Reduced ovarian or testicular hormone output — less production leads to low E2.
Lab timing — testing during a low point in the cycle can show low E2.

How Estradiol (E2) Relates to Other Values

Estradiol is often read with other hormone markers, such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone, and testosterone. In hormone panels, E2 helps describe estrogen activity while FSH and LH show signaling from the brain to the reproductive organs. When Estradiol on a lab report is considered alongside testosterone, the pattern can show how the balance of sex hormones is shifting. Unlike CBC markers such as hemoglobin, hematocrit (Hct), RBC, and MCV, E2 reflects hormone levels rather than red blood cell features.

What Factors Affect Estradiol (E2) Levels?

E2 naturally varies by age, sex, and reproductive stage, so the Estradiol reference range is not the same for every person. Time of day, recent exercise, and short-term fluid balance can also change an Estradiol test result a little. Body composition, diet pattern, alcohol intake, and liver processing may influence how much E2 stays in circulation. Different laboratories may use different assay methods, so the same sample can read slightly differently across labs. Because of this, an Estradiol on a blood test is best compared with the lab’s own reference range and the prior test timing.

How It Is Tested

The E2 test is done from a standard blood draw. The lab measures estradiol in the serum or plasma and reports the Estradiol test result in units such as pg/mL or pmol/L. Estradiol on a blood test is usually a single-point measurement taken from the collected sample.

How to Prepare

No fasting is usually required for an E2 test. Timing can matter because Estradiol on a lab report may shift with cycle day, treatment timing, and time of collection.

Frequently Asked Questions

What is a normal E2 level?
A normal E2 level depends on sex, age, and collection timing. For many adult males, the Estradiol reference range is about 10 to 40 pg/mL, while adult female values can vary much more across cycle stage and treatment patterns. The lab report’s own reference interval is the best match for the Estradiol test result.
What does E2 stand for?
E2 stands for estradiol, which is the main form of estrogen measured in many hormone panels. On a lab report, E2 is the shorthand used for Estradiol. The term can appear as Estradiol, E2, or Estradiol (E2).
What does a high Estradiol mean on a lab report?
A high Estradiol result usually means more estradiol is circulating than the reference group expects. In practice, high E2 can reflect a normal hormone peak, medication exposure, or changes in hormone metabolism. The exact meaning depends on the Estradiol test result, the lab’s reference range, and collection timing.
What does a low Estradiol mean on a lab report?
A low Estradiol result usually means less estradiol is circulating than expected for that reference group. A low E2 can appear with natural cycle lows, lower hormone production, or certain medications. The meaning is best judged against the lab’s Estradiol normal range and the timing of the blood draw.
Can hydration affect Estradiol?
Hydration can affect measured concentrations a little because fluid balance changes how concentrated the blood sample is. That effect is usually smaller than the effect of cycle timing, medication, or pregnancy. So a very small change in E2 between tests may reflect normal variation rather than a true shift.
What is the difference between Estradiol and testosterone?
Estradiol (E2) is a major estrogen signal, while testosterone is a major androgen signal. They are often reviewed together because they show different parts of the hormone balance on a blood test. An Estradiol test result does not measure testosterone, and testosterone does not measure E2.
What unit is Estradiol measured in?
Estradiol is most often measured in pg/mL in the United States, and some labs report pmol/L. The unit is listed next to the Estradiol test result on the lab report. The reference range only makes sense when the unit is read with the value.
How much can Estradiol change between tests?
E2 can change noticeably between tests because it varies with cycle stage, treatment timing, and time of day. Small shifts may be normal, especially when the first and second samples were taken at different points in a hormone cycle. Large changes are more likely when the underlying hormone pattern has changed or the sample timing differed a lot.
Is Estradiol different for men and women?
Yes. The Estradiol normal range is usually lower in adult males and broader in adult females because E2 reflects different baseline hormone patterns. That is why the same Estradiol test result can be interpreted differently across groups.
Why is Estradiol tested in a hormones panel?
Estradiol is tested in a hormones panel because it adds a direct measure of estrogen activity. The E2 result is often read with FSH, LH, progesterone, and testosterone to show how the hormone system is balanced. On a lab report, E2 helps complete the hormone picture rather than stand alone.

Disclaimer

This content is for informational and educational purposes only. It is not intended as medical advice, diagnosis, or treatment recommendation. Reference ranges may vary by laboratory. Always discuss your results with a qualified healthcare professional.

Related Tests

Testosterone

Testosterone is a hormone measured in blood that helps describe hormone balance and related body functions. On a lab report, Testosterone on a blood test is often reviewed for pattern changes over time and alongside other markers. The Testosterone normal range depends on sex, age, lab method, and the units used.

→
Free Testosterone

Free Testosterone is the unbound portion of testosterone circulating in blood. It is the fraction not attached to carrier proteins, so it is the part most available for biologic activity. On a blood test, Free Testosterone helps show how much testosterone is circulating in a usable form and is often read alongside total testosterone and sex hormone–binding globulin (SHBG).

→
Progesterone

Progesterone is a steroid hormone measured in blood to show how much of this hormone is circulating at the time of testing. On a lab report, Progesterone helps describe hormone patterns across different sex and reproductive states, and results are often read as part of a broader Hormones panel. The Progesterone test result is usually reported in ng/mL or nmol/L, and the Progesterone reference range depends on age and sex.

→
Cortisol

Cortisol is a steroid hormone made by the adrenal glands and measured in blood tests to show how much Cortisol is circulating at the time of collection. On a lab report, it helps describe hormone balance, time-of-day variation, and how the body is responding to stress, activity, and other factors. Because Cortisol changes across the day, the Cortisol test result is usually interpreted with the collection time and the lab’s Cortisol normal range.

→
DHEA-Sulfate DHEA-S

DHEA-Sulfate (DHEA-S) is a steroid hormone made mainly by the adrenal glands and measured in blood. On a DHEA-S lab report, the value helps show how much sulfate-bound androgen precursor is circulating. Results are often read with age, sex, and other hormone markers because normal DHEA-S levels vary widely.

→
Parathyroid Hormone PTH

Parathyroid Hormone (PTH) is a hormone measured in blood to show how much parathyroid signal is circulating at the time of the test. PTH on a lab report helps describe how the body is regulating calcium and related minerals. The result is often interpreted with other markers and the Parathyroid Hormone reference range for the same lab method.

→