- Also Known As:
- Estrogen Fractions/fractionated
- Estrone (E1)
- Estradiol (E2)
- Estriol (E3)
- Estrogenic Hormones
At a Glance
When To Get Tested?
Women: when you show symptoms of a hormone imbalance, such as abnormal vaginal bleeding, lack of menstrual periods, unusual and/or early or late sex organ development; when you are undergoing infertility treatment or therapy for menopause symptoms; when you are pregnant and your healthcare practitioner wants to monitor the health of your placenta and developing baby, if it is a high-risk pregnancy
Men: when you have signs of feminization, such as enlarged breasts (gynecomastia)
A blood sample drawn from a vein or a 24-hour urine sample
Test Preparation Needed?
None, but the timing of a woman’s sample will be correlated with her menstrual cycle or, if pregnant, with the gestational age of the baby.
What is being tested?
Estrogens are a group of steroids that are responsible for the development and function of reproductive organs and the formation of secondary sex characteristics in women. Along with another hormone, progesterone, they help regulate the menstrual cycle, are involved in the growth of breasts and the uterus, and help maintain a healthy pregnancy. Though considered the main sex hormones for women, they are also found in men and play…
Estrogens are a group of steroids that are responsible for the development and function of reproductive organs and the formation of secondary sex characteristics in women. Along with another hormone, progesterone, they help regulate the menstrual cycle, are involved in the growth of breasts and the uterus, and help maintain a healthy pregnancy. Though considered the main sex hormones for women, they are also found in men and play a role in bone metabolism and growth in both sexes. Estrogen tests measure one of three components: estrone (E1), estradiol (E2), or estriol (E3) in the blood or urine.
- Estrone (E1) is directly converted from androstenedione (from the adrenal gland) or indirectly from other androgens. E1 can also be produced by the ovaries and placenta, testicles, and adipose (fat) tissues. E2 and E1 can be converted into each other as needed. E1 is the primary estrogen in men and in post-menopausal women.
- Estradiol (E2) is primarily produced in the ovaries under stimulation of FSH and LH in pre-menopausal women and in the testicles in men. E2 is converted from E1 in post-menopausal women. It is the most potent estrogen and the one that is present in the highest concentration in non-pregnant, pre-menopausal women. E2 levels vary depending on a woman’s age and reproductive status. They are a good marker of ovarian function.
- Estriol (E3) is produced by the placenta, with concentrations rising throughout a woman’s pregnancy. Increasing levels are an indication of the health of the pregnancy and developing baby. Estriol is part of the second trimester maternal serum screen, a test performed to evaluate fetal risk due to certain chromosomal abnormalities. Very low levels of E3 are present in non-pregnant women or men.
Estrogen in Girls and Women
The types and amounts of estrogen normally present in a woman’s blood will vary throughout her lifetime. Levels vary during each menstrual cycle, during pregnancy, and on a daily basis.
Estradiol (E2) and estrone (E1) are high but fall within a few days. Concentration levels are minimal during early childhood.
Concentrations of E2 and E1 begin to rise as puberty approaches. These estrogens are responsible for the development of breasts, uterine growth, and (with other hormones) the onset and regulation of menstruation. A moderate amount of E1 is present from puberty to menopause. This concentration will vary during the day but is otherwise relatively stable.
The menstrual cycle is approximately 28 days long and consists of two phases, follicular phase (day 1-14) and luteal phase (day 15-28). During each cycle, estradiol (E2) and several other hormones normally rise and then fall in a specific sequence.
Estriol (E3) is the primary estrogen present during pregnancy. It is produced by the placenta, starts to rise in the eighth week of pregnancy, and continues to rise throughout the pregnancy. A sharp increase of E3 occurs approximately 4 weeks prior to the onset of labor. Estriol circulating in maternal blood is quickly cleared out of the body. Each measurement of estriol is a snapshot of what is happening with the placenta and fetus, but there is also natural daily variation in estriol concentrations.
E1 also rises during pregnancy, increasing as much as 10-fold between weeks 24 and 40. After delivery, E1 falls and E3 again becomes essentially undetectable.
Estrone (E1) is the primary estrogen present during menopause. E2 concentrations significantly decrease as ovarian production wanes and eventually stabilize at a low level.
Estrogen in Boys and Men
The types and amounts of estrogen normally present in a man’s blood change, but they vary much less over time than a woman’s and they are much lower.
How is it used?
Estrogen tests are used to detect a deficiency or excess in a woman and to help diagnose a variety of conditions associated with this imbalance. They may also be used to help determine the timing of a woman’s ovulation and may be ordered to monitor the health status of the developing baby and placenta during pregnancy. In a man, estrogen testing may be performed to detect a hormone excess and its cause.
Estrogen tests measure one of three components: estrone (E1), estradiol (E2), or estriol (E3). These tests each have different uses.
In Girls and Women
Estradiol (E2) and/or estrone (E1) testing may be ordered to:
- Help diagnose early-onset puberty, when a young girl develops secondary sex characteristics sooner than expected; or delayed puberty, when a girl shows delayed development of secondary sex characteristics or start of menstruation
- Investigate menstrual abnormalities, such as lack of menstrual periods (amenorrhea), infertility, and abnormal vaginal bleeding
- Evaluate the function of the ovaries and detect ovarian failure
- Monitor follicle development in the ovary in the days prior to in vitro fertilization by making serial measurements of estradiol
- Monitor hormone replacement therapy that is given to assist fertility
- Monitor menopausal hormone replacement therapy that is given to alleviate symptoms associated with estrogen deficiency
- Detect estrogen-producing tumors
- Monitor anti-estrogen therapy, as in breast cancer
Estriol (E3) testing:
- May sometimes be ordered serially to help monitor a high-risk pregnancy; when it is used this way, each sample should be drawn at the same time each day.
- An unconjugated estriol test is one of the components of second trimester maternal serum screening. Decreased levels have been associated with various genetic disorders, including Down syndrome, neural tube defects, and adrenal abnormalities.
In Boys and Men
Estradiol (E2) and/or estrone (E1) testing in boys or men may be ordered to:
- Help diagnose delayed puberty
- Help diagnose the cause of enlarged breasts (gynecomastia) or other signs of feminization
- Detect a relative estrogen excess that is due to a testosterone or androgen deficiency
- Detect estrogen-producing tumors
When is it ordered?
In Girls and Women
Estradiol (E2) and/or estrone (E1) testing in girls and women may be ordered when:
- A girl’s sex organs develop earlier or later than normally expected
- A woman has symptoms such as abnormal vaginal bleeding after menopause or abnormal or lack of menstrual cycles
- A woman is experiencing infertility; a series of estradiol measurements over the course of a woman’s menstrual cycle may be done to monitor follicle development prior to in vitro fertilization techniques (timed with a surge in estradiol).
- A woman is having symptoms of menopause, including hot flashes, night sweats, insomnia, and/or irregular or lack of menstrual periods
- A menopausal woman is taking hormone replacement therapy; her health practitioner may periodically order estrone levels to monitor treatment.
Estriol (E3) testing in women may be ordered:
- During pregnancy, a healthcare practitioner may order serial estriol samples to look for a trend, whether there is a rise or fall in the estriol level over time.
- Unconjugated estriol is often measured in the 15th to 20th week of gestation as part of the triple/quad screen.
In Boys and Men
Estradiol (E2) and/or estrone (E1) testing in boys and men may be ordered when:
- A boy has delayed puberty, characterized by delayed development of muscle mass, lack of deepening of the voice or growth of body hair, slow or delayed growth of testicles and penis
- A man shows signs of feminization, such as enlarged breasts
What does the test result mean?
Normal estrogen results depend upon the sex and age of the person being tested. With women, it also depends upon their menstrual cycle or whether they are pregnant. Reference ranges will vary somewhat between laboratories, both in normal values listed and in units used.
Increased or decreased levels of estrogens are seen in many metabolic conditions. Care must be used in the interpretation of estrone, estradiol, and estriol results because the levels vary on a day-to-day basis and throughout a woman’s menstrual cycle.
A healthcare practitioner who is monitoring a woman’s hormones will be looking at trends in the levels, rising or lowering over time in conjunction with the menstrual cycle or pregnancy rather than evaluating single values. Test results are not diagnostic of a specific condition but give the healthcare practitioner information about the potential cause of a person’s symptoms or status.
Below are conditions with which one might see an increase or decrease of estrogen levels.
Increased levels of estradiol (E2) or estrone (E1) are seen in:
Girls and Women:
- Early (precocious) puberty
- Tumors of the ovary or adrenal glands
Boys and Men:
- Enlarged breasts (gynecomastia)
- Tumors of the testicles (testicular cancer) or adrenal glands
- Delayed puberty
Both Women and Men:
In women, decreased levels of estrogen are seen in:
- Turner syndrome, an inherited condition in women caused by a missing or abnormal X chromosome and characterized by underdeveloped female sex characteristics
- Low level of pituitary hormones (hypopituitarism)
- Dysfunction of the ovaries (female hypogonadism)
- Failing pregnancy (estriol)
- Eating disorders such as anorexia nervosa
- After menopause (estradiol)
- Polycystic ovary syndrome (PCOS, also called Stein-Levanthal syndrome)
- Extreme endurance exercise
Is there anything else I should know?
Blood and urine results are not interchangeable. Your healthcare practitioner will choose which estrogen and sample type to test. In addition to blood and urine, estrogen testing is occasionally also performed on saliva or on amniotic fluid.
Do all men have estrogens?
Yes. Although they are present in amounts far less than in women, they are present and are needed for hormonal balance and the function of other glands.
What are estrogen receptors?
Estrogen receptors are proteins in cells from certain tissues that bind with estrogen. This binding allows estrogen to act on these tissues. Tumors can also have estrogen receptors. Estrogen can stimulate the growth of estrogen receptor-positive tumors in women who have breast cancer. Drugs that block the effect of estrogen may slow the rate of growth of such cancers. See the article on Estrogen/Progesterone Receptor Status for more on this.
What are phytoestrogens and environmental estrogens?
Phytoestrogens are estrogen-like compounds from plant sources. The two main classes are isoflavones, found in soy products, and lignans, found in whole grains and some fruits and vegetables. It has been proposed that these products could be used as an alternative to hormone replacement therapy (HRT). Initial studies have shown the relief of some menopausal symptoms, such as hot flashes, but there is more research yet to be done.
Environmental estrogens are chemicals, either natural (such as plant sources) or man-made (such as the insecticide DDT), that mimic the effect of estrogen and may cause disorders such as infertility, overgrowth of the endometrial lining, premature breast development, and feminization in young males. They tend to stay in the body for long periods of time and are being studied for their long-term effects.
Sources Used in Current Review
White, C. et. al. (2017 July 17, Updated). Estradiol blood test. MedlinePlus Medical Encyclopedia. Available online at https://medlineplus.gov/ency/article/003711.htm. Accessed on 07/07/18.
Bielak, K. and Harris, G. (2017 June 27, Updated). Amenorrhea. Medscape Obstetrics & Gynecology. Available online at https://emedicine.medscape.com/article/252928-overview. Accessed on 07/07/18.
Genzen, J. et. al. (2018 June, Updated). Amenorrhea. ARUP Consult. Available online at https://arupconsult.com/content/amenorrhea. Accessed on 07/07/18.
(© 1995–2018). Estrogens, Estrone (E1) and Estradiol (E2), Fractionated, Serum. Mayo Clinic Mayo Medical Laboratories. Available online at https://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/84230. Accessed on 07/07/18.
(2014 November). What is Estrogen? Hormone Health Network. Available online at https://www.hormone.org/hormones-and-health/hormones/estrogen. Accessed on 07/07/18.
Knudtson, J. and McLaughlin, J. (2016 August, Updated). Female Reproductive Endocrinology. Merck Manual Professional Version. Available online at https://www.merckmanuals.com/professional/gynecology-and-obstetrics/female-reproductive-endocrinology/female-reproductive-endocrinology. Accessed on 07/07/18.
Sofronescu, A. (2015 March 18, Updated). Estradiol. Medscape Laboratory Medicine. Available online at https://emedicine.medscape.com/article/2089003-overview. Accessed on 07/07/18.
Sources Used in Previous Reviews
ACOG. (October 2001, Number 31). ACOG Practice Bulletin, Clinical Management Guidelines for Obstetrician-Gynecologists, Assessment of Risk Factors for Preterm Birth. American College of Obstetricians and Gynecologists [Guideline from Obstet Gynecol 2001:98:709-716]. Available online through http://www.acog.org.
MedlinePlus (3 October 2001). Medical Encyclopedia: Estrogen Overdose. U.S. National Library of Medicine, Bethesda, MD. MedlinePlus. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/002584.htm.
MedlinePlus (9 August 2001). Medical Encyclopedia: Estradiol – Test. U.S. National Library of Medicine, Bethesda, MD. MedlinePlus. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003711.htm.
Thomas, Clayton L., Editor (1997). Taber’s Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (1999). Mosby’s Diagnostic and Laboratory Test Reference 4th Edition: Mosby, Inc., Saint Louis, MO.
Well-Connected Report: Menopause, Estrogen Loss and Their Treatments (March 2001). What Are Other Disorders Affected by Estrogen? WebMDHealth, [On-line serial]. Available online at http://my.webmd.com/content/article/1680.52622.
ACOG (3 October 2001). Hormonal Contraception Studies Examine Easier Methods, Menstrual Regulation. American College of Obstetricians and Gynecologists [Press release]. Available online at http://www.acog.org/from_home/publications/press_releases/nr10-31-01-3.htm.
ACOG (31 March 2001). ERT and Endometrial Cancer Survivors. American College of Obstetricians and Gynecologists [Press release]. Available online at http://www.acog.org/from_home/publications/press_releases/nr03-31-01-3.htm.
AMWA (2000). Hormone Replacement Therapy and Breast Cancer Risk, Q & A. American Medical Women’s Association [On-line serial]. Available online at http://www.amwa-doc.org/healthtopics/hrt_breastcancer_qa.htm.
Women’s Health Information Center (June 2001). Efficacy of Estradiol for the Treatment of Depressive Disorders in Perimenopausal Women. The Journal of the American Medical Association [Abstract from Arch Gen Psychiatry. 2001;58:529-534]. Available online through http://www.ama-assn.org.
Moving Beyond Cancer (4 October 2001). Managing Menopausal Symptoms Hormonal transitions. Breastcancer.org [On-line medical information]. Available online at http://www.breastcancer.org/bey_cope_meno_horTran.html.
Drugs & Herbs (24 March 2000, Medically reviewed October 2001) Estradiol Tropical Patches. LycosHealth with WebMD [On-line Medical Information]. Available online at http://webmd.lycos.com/drug_article/article/4046.1242.
Association of Women for the Advancement of Research and Education Typical Hormone Products. Available online at http://www.project-aware.org/Managing/Hrt/HRTtoday.html.
ARUP’s Guide To Clinical Laboratory Testing. Estriol, Serum and Urine. Available online at http://www.aruplab.com/guides/clt/tests/clt_a201.htm.
ARUP’s Guide To Clinical Laboratory Testing. Maternal Serum Screening. Available online at http://www.aruplab.com/guides/clt/tests/clt_al60.htm#1208428.
Pagana, K. D. & Pagana, T. J. (© 2007). Mosby’s Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 416-419.
Clarke, W. and Dufour, D. R., Editors (© 2006). Contemporary Practice in Clinical Chemistry: AACC Press, Washington, DC. Pp 359-360.
S3 Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 366-369, 374-377.
(Updated 2009 September 29). Hormones and Menopause. National Institute on Aging [On-line information]. Available online at http://www.nia.nih.gov/HealthInformation/Publications/hormones.htm. Accessed November 2009.
Brzyski, R. and Jensen, J. (Revised 2007 March). Female Reproductive Endocrinology, Introduction. Merck Manual for Healthcare Professionals [On-line information]. Available online at http://www.merck.com/mmpe/sec18/ch243/ch243a.html#CACHDFBE. Accessed November 2009.
Vorvick, L. and Storck, S. (Updated 2009 July 26). Estradiol test. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003711.htm. Accessed November 2009.
(© 2013). Estrogen. The Hormone Doctor [On-line information]. Available online at http://thehormonedoctor.com/hormones/estrogen/. Accessed April 2014.
(© 1995-2013). Estrogens, Estrone (E1) and Estradiol (E2), Fractionated, Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/interpretive-guide/?alpha=E&unit_code=84230. Accessed April 2014.
Meikle, A. W. and Miller, C. (Updated 2013 July). ARUP Consult. Amenorrhea [On-line information]. Available online at http://www.arupconsult.com/Topics/Amenorrhea.html?client_ID=LTD#tabs=0. Accessed April 2014.
Coney, P. (Updated 2013 October 4). Menopause. Medscape Reference [On-line information]. Available online at [On-line information]. Available online at http://emedicine.medscape.com/article/264088-overview. Accessed April 2014.
Bielak, K. and Popat, V. (Updated 2012 June 5). Amenorrhea. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/252928-overview. Accessed April 2014.
(Reviewed 2013 May). Menopause. The Hormone Health Network [On-line information]. Available online at http://www.hormone.org/diseases-and-conditions/womens-health/menopause. Accessed April 2014.
Gass, M. (Revised 2013 August). Menopause. Merck Manual Home Health Handbook [On-line information]. Available online through http://www.merckmanuals.com. Accessed April 2014 .
Pagana, K. D. & Pagana, T. J. (© 2011). Mosby’s Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 425-428.
Clarke, W., Editor (© 2011). Contemporary Practice in Clinical Chemistry 2nd Edition: AACC Press, Washington, DC. Pp 425-428.