Luteinizing Hormone (LH)
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- Also Known As:
- LH
- Lutropin
- Interstitial Cell Stimulating Hormone
- ICSH

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At a Glance
Why Get Tested?
To evaluate fertility issues or the health of your reproductive organs (ovaries or testicles); for women, to determine whether you have ovulated (released an egg from the ovary); to evaluate pituitary function
In children, to evaluate early or delayed puberty
When To Get Tested?
For women, when you are having difficulty getting pregnant or are having irregular or heavy menstrual periods; when you are tracking ovulation during your menstrual cycle
For men, when your partner cannot get pregnant or you have a low sperm count, low muscle mass or decreased sex drive
When your health care provider thinks that you have symptoms of a pituitary disorder or hypothalamic disorder
When a health care practitioner suspects that a child has delayed or earlier than expected puberty
Sample Required?
A blood sample is drawn by needle from a vein.
Test Preparation Needed?
No test preparation is needed, but a woman’s sample should be collected at specific times during her menstrual cycle.
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What is being tested?
Luteinizing hormone (LH) is a hormone associated with reproduction. Its stimulation of either ovary or testicles results in the release of an egg from the ovary (ovulation) in women or testosterone production in men. This test measures the amount of luteinizing hormone in the blood.
LH is produced by the pituitary gland, a small organ located in the center of the head behind the sinus cavity at the base of the brain. Control of LH production is a complex system involving the hypothalamus in the brain, the pituitary gland, and the hormones produced by the ovaries and testicles.
In women of childbearing age, several hormones (LH, follicle-stimulating hormone (FSH), estrogen and progesterone) rise and fall in a specific sequence during each menstrual cycle. Womens’ menstrual cycles are divided into follicular and luteal phases, with each phase lasting about 14 days. Near the end of the follicular phase, there is a mid-cycle surge of FSH and LH. This surge triggers ovulation, causing the rupture of the egg follicle on the ovary and the release of the egg.
During the luteal phase, the site where the egg follicle ruptured becomes a “corpus luteum.” LH release stimulates the corpus luteum to start producing progesterone. FSH and LH levels decline, while progesterone and estradiol concentrations increase. These hormone levels decrease in turn after several days if the egg is not fertilized. Menstruation starts and when it ends, the cycle begins again.
As a woman ages and menopause approaches, ovarian function wanes and eventually ceases. As this occurs, FSH and LH levels rise.
In men, LH stimulates Leydig cells in the testicles to produce testosterone. LH levels are relatively constant in men after puberty. A high testosterone level provides negative feedback to the pituitary gland and the hypothalamus, thus decreasing the amount of LH released.
In infants and children, LH levels rise shortly after birth and then fall to very low levels (by 6 months in boys and 1-2 years in girls). At about 6-8 years, levels again rise before the beginning of puberty and the development of secondary sexual characteristics.
Common Questions
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The reference ranges for your tests can be found on your laboratory report. They are typically found to the right of your results.
If you do not have your lab report, consult your healthcare provider or the laboratory that performed the test(s) to obtain the reference range.
Laboratory test results are not meaningful by themselves. Their meaning comes from comparison to reference ranges. Reference ranges are the values expected for a healthy person. They are sometimes called “normal” values. By comparing your test results with reference values, you and your healthcare provider can see if any of your test results fall outside the range of expected values. Values that are outside expected ranges can provide clues to help identify possible conditions or diseases.
While accuracy of laboratory testing has significantly evolved over the past few decades, some lab-to-lab variability can occur due to differences in testing equipment, chemical reagents, and techniques. This is a reason why so few reference ranges are provided on this site. It is important to know that you must use the range supplied by the laboratory that performed your test to evaluate whether your results are “within normal limits.”
For more information, please read the article Reference Ranges and What They Mean.
View Sources
Sources Used in Current Review
Chen, P. (2017 August 26, Updated). Luteinizing hormone (LH) blood test. MedlinePlus Medical Encyclopedia. Available online at https://medlineplus.gov/ency/article/003708.htm. Accessed on 5/05/19.
Eaton, J. et. al. (2016 November 4, Updated). Luteinizing Hormone Deficiency. Available online at https://emedicine.medscape.com/article/255046-overview. Accessed on 5/05/19.
(© 1995–2018). Luteinizing Hormone (LH), Serum. Mayo Clinic Mayo Medical Laboratories. Available online at https://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/602752. Accessed on 5/05/19.
Jabbour, S. (2018 March 12, Updated). Follicle-Stimulating Hormone Abnormalities. Medscape Endocrinology. Available online at https://emedicine.medscape.com/article/118810-overview#showall. Accessed on 5/05/19.
Straseski, J. and Young, B. (2018 May, Updated). Male Hypogonadism. ARUP Consult. Available online at https://arupconsult.com/content/hypogonadism-male?_ga=2.126530189.1479446145.1525530915-171446445.1522145782. Accessed on 5/05/19.
Vogiatzi, M. (2018 February 11, Updated). Hypogonadism. Medscape Pediatrics: General Medicine. Available online at https://emedicine.medscape.com/article/922038-overview#showall. Accessed on 5/05/19.
Charbek, E. (2015 July 27, Updated). Luteinizing Hormone. Medscape Laboratory Medicine. Available online at https://emedicine.medscape.com/article/2089268-overview#showall. Accessed on 5/05/19.
Sources Used in Previous Reviews
Corbett, JV. Laboratory Tests & Diagnostic Procedures with Nursing Diagnoses, 4th ed. Stamford, Conn.: Appleton & Lang, 1996. pp. 429-431, 726.
Clinical Guide to Laboratory Tests. 3rd ed. Tietz N, ed. Philadelphia: W.B. Saunders & Co; 1995: 248-249, 210-211.
The InterNational Council on Infertility Information Dissemination. PCOS in Pediatrics: When and How Does it Start? Originally written and presented by Silva Arslanian, MD, Children’s Hospital of Pittsburgh, Pittsburgh, PA; summarized in online version by Christine M. Schroeder, PhD. Available online at http://www.inciid.org/pcos/PCOS-pediatrics.html.
Gonadotropins: Luteinizing and Follicle Stimulating Hormones. Available online at http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/hypopit/lhfsh.html.
Blondell RD, Foster MB, Kamlesh CD. Disorders of Puberty. American Family Physician, July 1999 (online publication). Available online at http://www.aafp.org/afp/990700ap/209.html.
Hormone Society. Fact Sheet on Female Infertility. Available online at http://www.endo-society.org/pubrelations/patientInfo/infertility.htm.
The Hormone Foundation. Fact sheet on Polycystic Ovary Syndrome (PCOS). Available online at http://www.hormone.org/pcos_factsheet.html.
Laurence M. Demers, PhD. Distinguished Professor of Pathology and Medicine, The Pennsylvania State University College of Medicine, The M. S. Hershey Medical Center, Hershey, PA.
A Manual of Laboratory & Diagnostic Tests. 6th ed. Fischbach F, ed. Philadelphia: Lippincott Williams & Wilkins; 2000.
Pagana K, Pagana T. Mosby’s Manual of Diagnostic and Laboratory Tests. St. Louis: Mosby; 1998.
Davis B, Mass D, Bishop M. Principles of Clinical Laboratory Utilization and Consultation. Saunders; 1999.
Thompason, Sharon. LH response to GnRH. (Updated Aug 2005) MedlinePlus (online information). Available online at http://www.nlm.nih.gov/medlineplus/print/ency/article/003709.htm.
Neely EK, Wilson DM, Lee PA, Stene M, Hintz RL (July 1995). Spontaneous serum gonadotropin concentrations in the evaluation of precocious puberty. J Pediatric 127(1):47-52 from PubMed. Available online at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=7608810.
Nirupama Kakarla, M.D.; Karen D. Bradshaw, M.D. (Posted 03/05/2004.) Disorders of Pubertal Development: Precocious Puberty. From Seminars in Reproductive Medicine 21(4):339-351 from Medscape. Available online at http://www.medscape.com/viewarticle/468259.
Brito VN, Batista MC, Borges MF, Latronico AC, Kohek MB, Thirone AC, Jorge BH, Arnhold IJ, Mendonca BB. (1999 Oct) Diagnostic value of fluorometric assays in the evaluation of precocious puberty. J Clin Endocrinol Metab. 84(10):3539-44.
Sheehan, M (Dec 2003). Polycystic Ovarian Syndrome: Diagnosis and Management. Clinical Medicine and Research, 2(1): 13-27. Available online at http://www.pubmedcentral.gov/articlerender.fcgi?artid+1069067.
Pagana, K. D. & Pagana, T. J. (© 2007). Mosby’s Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 629-631.
Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 694-697.
Vorvick, L. (Updated 2009 July 29). LH. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003708.htm. Accessed February 2010.
Giannios, N. et. al. (Updated 2008 February 12). Luteinizing Hormone Deficiency. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/255046-overview. Accessed February 2010.
Meikle, A. W. et. al. (Updated 2009 November). Amenorrhea. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/Amenorrhea.html#. Accessed February 2010.
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?qt=FSH&alt=sh. Accessed February 2010.
Clarke, W. and Dufour, D. R., Editors (© 2006). Contemporary Practice in Clinical Chemistry: AACC Press, Washington, DC. Pp 360-361.
Barker, N, et, al. (Updated 2012 March 23). Luteinizing Hormone Deficiency. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/255046-overview. Accessed April 2014.
Dowshen, S. (2011 March). Blood Test: Luteinizing Hormone (LH). KidsHealth from Nemours [On-line information]. Available online at http://kidshealth.org/parent/system/medical/blood_test_lh.html. Accessed April 2014.
Kaplowitz, P. (Updated 2013 February 11). Precocious Puberty. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/924002-overview. Accessed April 2014.
Meikle, A. and Straseski, J. (Updated 2013 November). Infertility. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/Infertility.html?client_ID=LTD#tabs=0. 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.
(© 1995–2014). LH. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/8663. Accessed April 2014.
Vorvick, L. (2013 September 30). LH blood test. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003708.htm. 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 649-651.
Clarke, W., Editor (© 2011). Contemporary Practice in Clinical Chemistry 2nd Edition: AACC Press, Washington, DC. Pp 471-479.
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