Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Categories
Subscribe to the Magazine for free
Subscribe for free to keep reading! If you are already subscribed, enter your email address to log back in.
Thanks for subscribing!
Oops! Something went wrong while submitting the form.
Are you a healthcare practitioner?
Thanks for subscribing!
Oops! Something went wrong while submitting the form.

Luteinizing Hormone Function: Key Player in Reproductive Health

Medically reviewed by 
 
Luteinizing Hormone Function: Key Player in Reproductive Health

Luteinizing hormone (LH) is a cornerstone of reproductive health, playing a pivotal role in both male and female reproductive systems. Produced by the anterior pituitary gland, LH is integral to the complex dance of hormones that underpin fertility, sexual development, and menstrual health. 

This article seeks to explore the multifaceted functions of LH, from its critical involvement in the hypothalamic-pituitary-gonadal axis to its impact on ovulation, testosterone production, and beyond.

[signup]

What is the Luteinizing Hormone?

Luteinizing hormone is a glycoprotein that is produced by the anterior pituitary as part of the hypothalamic-pituitary-gonadal (HPG) axis. To fully comprehend the role LH plays in reproduction, it is important to first take a moment to better understand the HPG axis. This axis is a complex interplay of neurotransmitters and hormones that coordinate together to regulate reproductive hormones.

Think of the HPG axis as a production line for estrogen, progesterone, and testosterone. Its main players, the hypothalamus, the pituitary, and the gonads (ovaries and testes), work together to ensure that the correct amount of reproductive hormones are being produced. Therefore, when estrogen and testosterone levels in the body drop, this signals the HPG axis to increase production. 

The hypothalamus responds by releasing gonadotropin-releasing hormone (GnRH) in a pulsatile fashion which sets the rhythm for the rate of production. When the beat is fast and frequent, production is spurred; when the beat is slow, production slows (2).

GnRH travels to the pituitary gland where its frequent pulses stimulate the release of LH and follicle-stimulating hormone (FSH). LH, along with FSH, then travels to the gonads to stimulate reproductive processes such as ovarian progesterone production in females and testosterone production from the testes in males. When production outpaces demand and estrogen, progesterone, and testosterone levels rise too high, they inhibit LH release by slowing down the pulsatile rhythm of GnRH, acting as part of a negative feedback loop that maintains hormonal homeostasis (2). 

The Role of LH in Female Reproductive Health

LH and FSH set the stage for ovulation and thus play a critical role in the menstrual cycle and reproduction. 

Ovulation and the Menstrual Cycle

LH and FSH work together to increase the production of estradiol from the ovarian follicle. LH starts the process by encouraging the production of androstenedione, an ovarian steroid, from the theca cells. FSH helps by producing the enzyme aromatase which converts androstenedione to estradiol (26). When estradiol levels are sustained at 200 pg/mL or more for at least 2 days, a positive feedback mechanism is employed in which the hypothalamus increases GnRH secretion, leading to an LH surge (2).

This surge prompts the maturation of the developing oocyte which then is released from the ovarian follicle approximately 24-36 hours later, a process called ovulation (35). LH test strips, commonly used for fertility planning, are testing for this LH surge as it coincides with the ideal ovulatory window for embryo production. 

LH and Hormonal Regulation

LH’s role does not end with ovulation. After ovulation the follicle turns into the corpus luteum, a temporary organ that produces the hormones progesterone and human chorionic gonadotropin (hCG) which are important for pregnancy. LH stimulates the production of progesterone from the corpus luteum, leading to the rise in progesterone during the luteal phase of the menstrual cycle.

Progesterone helps to prepare the endometrium (uterine lining) for the implantation of a fertilized oocyte. If fertilization of the egg occurs, the corpus luteum will start to produce hCG maintaining the high levels of progesterone needed for proper implantation and early embryonic growth. If, however, no fertilization occurs by day 14 after ovulation, the corpus luteum breaks down and is reabsorbed back into the ovary. This results in the cessation of progesterone production which in turn causes the lining to shed as part of menstruation (29). 

The Role of LH in Male Reproductive Health

LH is also vital to the male reproductive system through its stimulatory action on testosterone production. 

Testosterone Production

LH plays an essential role in testosterone production and male sexual development via the development of Leydig cells. LH is released in pulses stimulated by GnRH action on the pituitary and travels to the testes where it attaches to receptors on the surface of Leydig cells. This binding stimulates the production of testosterone from the testes, which in turn is critical for sperm production, the development of secondary sex characteristics, and important psychological and metabolic effects (28). The Leydig cells also play a role in the urogenital development of male embryos through the release of androgens that induce this process (1). 

Impact on Sperm Maturation

LH along with FSH is involved in the production and quality of sperm. By stimulating testosterone, LH initiates the process of sperm production. In the presence of testosterone, FSH acts on Sertoli cells in the testes which enables the maturation of sperm and overall sperm quality (28).

During puberty, LH pulse frequency increases, causing Leydig cells in the testes to multiply and mature. More Leydig cells lead to higher testosterone levels within the testes which is necessary for maintaining sperm production. Testosterone levels are kept in check by its inhibitory action on LH. When testosterone levels reach too high, the pulsatile frequency of GnRH slows down, lowering the stimulation of LH which in turn lowers the production of testosterone (26). 

Luteinizing Hormone Imbalances

Despite the complex system of checks and balances within the HPG axis, imbalances sometimes occur leading to detrimental effects on reproductive wellness. 

High LH Levels

As mentioned previously, LH production can be inhibited by high levels of circulating sex steroids such as testosterone and estrogen. Therefore, when LH levels are consistently high, there likely is insufficient sex steroid production coming from the ovaries or testicles, impacting reproductive processes and function. 

In women, high LH levels are often implicated in polycystic ovarian syndrome (PCOS). Patients with PCOS lack the cyclical pattern of LH and FSH that maintains a healthy menstrual cycle. Instead, LH levels tend to be high while FSH levels are suppressed. This can lead to abnormal menstrual cycles and issues with fertility. In a study that followed PCOS patients who were experiencing fertility issues versus those who were not, LH levels were significantly higher in the infertile group.

One explanation for this is that the high LH levels correlated with poor oocyte quality and development, impacting embryonic development (35). During menopause, LH levels significantly increase and remain elevated as the ovaries no longer produce estradiol. 

In men, high levels of LH can be a sign of primary hypogonadism in which the testes fail to produce adequate levels of testosterone. Low testosterone can lead to poor sperm production and poor sperm quality resulting in fertility issues. In addition, low testosterone levels can result in additional symptoms such as low libido, erectile dysfunction, depression, fatigue, and osteoporosis. Primary hypogonadism can be caused by genetic defects, testicular injury, chemotherapy, radiation, and excessive alcohol intake (12).  

Low LH Levels

On the other end of the spectrum are low LH levels. These levels are often caused by issues at the hypothalamus or the pituitary rather than a loss of negative feedback from estrogen and testosterone. Low LH levels are found in male secondary hypogonadism, which like primary hypogonadism, is also correlated with low testosterone levels and thus is associated with similar symptoms. Low testosterone in this case results from the lack of LH stimulation of Leydig cells (12). Low LH levels can also be caused by insufficient energy intake, when caloric intake is outpaced by caloric loss such as through excessive exercise (34). 

Testing for Luteinizing Hormone Levels

As LH plays a pivotal role in menstrual health, fertility, and sex hormone production, it can be an important indicator of dysfunction in these areas, and is often included in hormone test panels.

Indications for LH Testing

There can be many reasons why a provider would want to include LH testing as part of an overall hormonal assessment. Because LH imbalances can result in fertility issues in all genders, its testing can help pinpoint possible causes such as low spermatogenesis or irregular ovulation. LH testing along with serum testosterone levels can also help identify cases of hypogonadism in men experiencing symptoms of low testosterone (12). Although not enough to diagnose menopause on its own, LH levels can help indicate whether menopause status is likely. 

Understanding LH Test Results

When using LH tests to help understand fertility or menstrual cycle issues in women, timing is important as LH fluctuates normally in a healthy menstrual cycle. Testing for fertility often starts in the middle of the follicular phase to catch the LH surge that indicates impending ovulation. In this case, an absent or deficient LH surge could indicate an anovulatory cycle. Monitoring the LH surge for changes can be used as a way to assess efficacy in fertility treatments.

LH testing is particularly important during the use of fertility-assisted reproductive technologies to help determine appropriate timing. When used to assess for menopause status, high levels of LH can indicate a positive likelihood, especially when accompanied by high FSH and low estradiol and progesterone levels. 

In men, testing for LH in cases of low testosterone can help distinguish primary hypogonadism from secondary hypogonadism. In primary hypogonadism, LH levels are elevated while in secondary hypogonadism, LH levels are low to normal (12). 

[signup]

Managing Luteinizing Hormone Imbalances

Treating LH imbalances involves finding the root cause of the issue to correct dysregulation. Depending on the underlying issue, medical treatments such as hormone therapy may be indicated, and/or dietary and lifestyle changes. 

Medical Treatments

For fertility enhancement, the use of appropriately timed LH supplementation has been used to varying effect. While some studies suggest that LH supplementation during the second half of the follicular phase can help improve follicle quality and embryo production, thereby improving fertility outcomes, other studies demonstrated little to no improvement with LH supplementation. It may be that the efficacy of LH supplementation depends on specific populations, such as women over 35, and the concomitant use of other treatments such as FSH and gonadotropin. 

Because the symptoms of both male primary and secondary hypogonadism stem from low testosterone, testosterone replacement therapy is an important treatment option to help alleviate these symptoms either as a monotherapy or as a larger comprehensive plan (12). 

Lifestyle and Dietary Considerations

Diet can play an important role in LH production, especially in cases where undernourishment is present. When energy expenditure exceeds energy intake, the body interprets this as an unsafe situation in which to encourage reproduction. Therefore, reproductive processes are put on hold by slowing GnRH pulsation and with it, the stimulation of LH (34). A nutrient-rich diet that meets the energetic demands of the body can help maintain healthy LH levels. Additionally, improvements in semen quality occurred when men incorporated healthy levels of carbohydrates, fiber, and foods rich in lycopene and folate, suggesting indirect actions on LH (34).

A healthy exercise regimen is also vital. Moderate exercise can be beneficial to LH production, whereas prolonged high-intensity and high-weight-resistance exercises have been shown to decrease LH stimulation and testosterone levels in men for up to 12 hours. Additionally, excessive exercise has been linked to menstrual cycle irregularities and sometimes cycle cessation in women (34). 

Mitigating lifestyle behaviors such as drinking alcohol, smoking, and stress is important as excesses of these have been shown to interfere with GnRH pulsation, thus causing dysregulation of the HPG axis, including altered LH levels (34). 

[signup]

Key Takeaways

Luteinizing hormone (LH) plays a vital role in the orchestration of reproductive functions, facilitating crucial processes from ovulation in women to testosterone production in men. As a linchpin in the regulation of the menstrual cycle, fertility, and sexual development, balanced levels of LH are paramount for optimal reproductive health. Disruptions in LH levels can lead to a range of reproductive challenges, including polycystic ovarian syndrome (PCOS) and hypogonadism. 

If you suspect an imbalance in your LH levels or face reproductive health issues, consulting with healthcare professionals can provide you with the guidance and treatments needed for managing your health proactively. Early detection and intervention can be key in navigating the complex interplay of hormones that support our reproductive systems, reinforcing the importance of attentiveness and care in maintaining our overall well-being.

The information provided is not intended to be a substitute for professional medical advice. Always consult with your doctor or other qualified healthcare provider before taking any dietary supplement or making any changes to your diet or exercise routine.
Learn More
No items found.

Lab Tests in This Article

No items found.
  1. Aladamat, N., & Tadi, P. (2022). Histology, Leydig Cells. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK556007/#:~:text=Leydig%20cells%20are%20the%20primary
  2. Barbieri, R. L. (2014). The endocrinology of the menstrual cycle. Methods in Molecular Biology (Clifton, N.J.), 1154, 145–169. https://doi.org/10.1007/978-1-4939-0659-8_7
  3. Christie, J. (2023a, January 31). 7 Functional Medicine Labs to Test for Root Cause of Infertility in Women. Rupa Health. https://www.rupahealth.com/post/7-functional-medicine-labs-to-test-for-root-cause-of-infertility-in-women
  4. Christie, J. (2023b, January 31). 7 Functional Medicine Labs to Test That Can Help Diagnose The Root Cause of Infertility in Men. Rupa Health. https://www.rupahealth.com/post/7-functional-medicine-labs-to-test-for-root-cause-of-infertility-in-men
  5. Cleveland Clinic. (2022). Luteinizing Hormone: Levels, Function & Testing. Cleveland Clinic. https://my.clevelandclinic.org/health/body/22255-luteinizing-hormone
  6. Cloyd, J. (2023a, March 7). An integrative medicine approach to fatigue. Rupa Health. https://www.rupahealth.com/post/an-integrative-medicine-approach-to-fatigue
  7. Cloyd, J. (2023b, July 20). A functional medicine PCOS protocol: Comprehensive testing, therapeutic diet, and supplements. Rupa Health. https://www.rupahealth.com/post/a-functional-medicine-pcos-protocol-comprehensive-testing-therapeutic-diet-and-supplements
  8. Cloyd, J. (2024a, February 28). The Link Between Erectile Dysfunction and Cardiovascular Disease: Understanding the Connection. Rupa Health. https://www.rupahealth.com/post/the-link-between-erectile-dysfunction-and-cardiovascular-disease-understanding-the-connection
  9. Cloyd, J. (2024b, March 1). Optimizing Sperm Health for Male Fertility Outcomes. Rupa Health. https://www.rupahealth.com/post/optimizing-sperm-health-for-male-fertility-outcomes
  10. Cloyd, K. (2023a, July 3). Functional Medicine Lab Tests That Can Help Individualize Treatment for Patients With Andropause. Rupa Health. https://www.rupahealth.com/post/functional-medicine-lab-tests-that-can-help-individualize-treatment-for-patients-with-andropause
  11. Cloyd, K. (2023b, November 7). Men’s Hormonal Symphony: The Crucial Role of Adrenals, Thyroid, and Testes. Rupa Health. https://www.rupahealth.com/post/mens-hormonal-symphony-the-crucial-role-of-adrenals-thyroid-and-testes
  12. Dandona, P., & Rosenberg, M. T. (2010). A practical guide to male hypogonadism in the primary care setting. International Journal of Clinical Practice, 64(6), 682–696. https://doi.org/10.1111/j.1742-1241.2010.02355.x
  13. DeCesaris, L. (2023a, January 25). How to Support a Healthy Menstrual Cycle. Rupa Health. https://www.rupahealth.com/post/how-to-support-a-healthy-menstrual-cycle
  14. DeCesaris, L. (2023b, August 16). How To Test For Female Hormones: A Comprehensive Guide. Rupa Health. https://www.rupahealth.com/post/how-to-test-for-female-hormones-a-comprehensive-guide
  15. Diorio, B. (2023, April 7). Could your patients benefits from the phytonutrient spectrum food plan? Rupa Health. https://www.rupahealth.com/post/could-your-patients-benefits-from-the-phytonutrient-spectrum-food-plan
  16. Easthope, A. (2022, April 26). 11 Common Causes Of Low Male Testosterone (And How To Fix Them). Rupa Health. https://www.rupahealth.com/post/an-integrative-medicine-approach-to-low-male-testosterone-hypogonadism
  17. Huang, C., Shi, Q., Yan, Y., Shen, X., Shan, H., Zhu, Y., Sun, H., Xing, J., & Kong, N. (2022). Effect of Exogenous Luteinizing Hormone (LH) Supplementation on Clinical Pregnancy of Patients Receiving Long-Acting Gonadotropin-Releasing Hormone Agonist (GnRHa) Cycles: A Retrospective Cohort Study. International Journal of Women’s Health, Volume 14, 1691–1700. https://doi.org/10.2147/ijwh.s388726
  18. Humaidan, P., Bungum, M., Bungum, L., & Yding Andersen, C. (2004). Effects of recombinant LH supplementation in women undergoing assisted reproduction with GnRH agonist down-regulation and stimulation with recombinant FSH: an opening study. Reproductive BioMedicine Online, 8(6), 635–643. https://doi.org/10.1016/s1472-6483(10)61643-4
  19. Kalaichandran, A. (2024, February 23). Extinguishing the Habit, Igniting Life: The Transformative Impact of Quitting Smoking. Rupa Health. https://www.rupahealth.com/post/extinguishing-the-habit-igniting-life-the-transformative-impact-of-quitting-smoking
  20. Kazmi, S. R. H., & Can, A. S. (2022). Luteinizing Hormone Deficiency. PubMed; StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/32965890/
  21. Khakham, C. (2023, October 5). Top Labs To Run Bi-Annually On Your Patients Going Through Menopause. Rupa Health. https://www.rupahealth.com/post/top-labs-to-run-bi-annually-on-your-patients-going-through-menopause
  22. Kresge, K. (2023, February 21). An Integrative Medicine Approach to Depression. Rupa Health. https://www.rupahealth.com/post/an-integrative-medicine-approach-to-depression
  23. LoBisco, S. (2022, November 16). 7 Natural Treatments For Low Progesterone. Rupa Health. https://www.rupahealth.com/post/progesterone-imbalance-signs-treatments
  24. Luteinizing Hormone (LH) Levels Test: MedlinePlus Medical Test. (n.d.). Medlineplus.gov. Retrieved March 27, 2024, from https://medlineplus.gov/lab-tests/luteinizing-hormone-lh-levels-test/#:~:text=In%20men%2C%20LH%20causes%20the
  25. Maholy, N. (2023, April 14). How to reduce stress through mind-body therapies. Rupa Health. https://www.rupahealth.com/post/how-to-reduce-stress-through-mind-body-therapies
  26. Nedresky, D., & Singh, G. (2020). Physiology, Luteinizing Hormone. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK539692/
  27. Nindl, B. C., Kraemer, W. J., Deaver, D. R., Peters, J. L., Marx, J. O., Heckman, J. T., & Loomis, G. A. (2001). LH secretion and testosterone concentrations are blunted after resistance exercise in men. Journal of Applied Physiology, 91(3), 1251–1258. https://doi.org/10.1152/jappl.2001.91.3.1251
  28. Oduwole, O. O., Huhtaniemi, I. T., & Misrahi, M. (2021). The Roles of Luteinizing Hormone, Follicle-Stimulating Hormone and Testosterone in Spermatogenesis and Folliculogenesis Revisited. International Journal of Molecular Sciences, 22(23), 12735. https://doi.org/10.3390/ijms222312735
  29. Oliver, R., & Pillarisetty, L. S. (2023, January 1). Anatomy, Abdomen and Pelvis, Ovary Corpus Luteum. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK539704/
  30. Perera, H. (2024, March 11). Anterior Pituitary (Its Hormones, Functions, & More). Rupa Health. https://www.rupahealth.com/post/hormones-by-anterior-pituitary
  31. Preston, J. (2023a, February 15). Hypothalamic-Pituitary-Ovarian (HPO) Axis Dysfunction: Lab Testing, Diagnosis, and Treatment. Rupa Health. https://www.rupahealth.com/post/hypothalamic-pituitary-ovarian-hpo-axis-dysfunction-lab-testing-diagnosis-and-treatment
  32. Preston, J. (2023b, August 1). The Role of Integrative Nutrition in Supporting Pregnancy. Rupa Health. https://www.rupahealth.com/post/the-role-of-integrative-nutrition-in-supporting-pregnancy
  33. Rahman, N. A., & Rao, C. V. (2009). Recent progress in luteinizing hormone/human chorionic gonadotrophin hormone research. Molecular Human Reproduction, 15(11), 703–711. https://doi.org/10.1093/molehr/gap067
  34. Sharma, R., Biedenharn, K. R., Fedor, J. M., & Agarwal, A. (2013). Lifestyle factors and reproductive health: taking control of your fertility. Reproductive Biology and Endocrinology, 11(1), 66. https://doi.org/10.1186/1477-7827-11-66
  35. Shoham, Z., Jacobs, H. S., & Insler, V. (1993). Luteinizing hormone: its role, mechanism of action, and detrimental effects when hypersecreted during the follicular phase. Fertility and Sterility, 59(6), 1153–1161. https://doi.org/10.1016/S0015-0282(16)55968-8
  36. Su, H.-W., Yi, Y.-C., Wei, T.-Y., Chang, T.-C., & Cheng, C.-M. (2017). Detection of ovulation, a Review of Currently Available Methods. Bioengineering & Translational Medicine, 2(3), 238–246. https://doi.org/10.1002/btm2.10058
  37. Sweetnich, J. (2023a, February 28). Testosterone Testing 101. Rupa Health. https://www.rupahealth.com/post/testosterone-testing-101
  38. Sweetnich, J. (2023b, April 17). A Functional Medicine Protocol for Low Libido in Men. Rupa Health. https://www.rupahealth.com/post/a-functional-medicine-protocol-for-low-libido-in-men
  39. Sweetnich, J. (2023c, April 21). Functional Medicine Labs and Supplements to Support Each Phase of the Menstrual Cycle. Rupa Health. https://www.rupahealth.com/post/functional-medicine-labs-and-supplements-to-support-each-phase-of-the-menstrual-cycle
  40. Sweetnich, J. (2023d, May 8). Understanding the Importance of Folate Testing and Proper Supplementation for Optimal Health. Rupa Health. https://www.rupahealth.com/post/understanding-the-importance-of-folate-testing-and-proper-supplementation-for-optimal-health
  41. Teeter, L. A. (2023, April 19). Natural Ways to Increase Fertility Through Complementary and Integrative Medicine. Rupa Health. https://www.rupahealth.com/post/natural-ways-to-increase-fertility-through-complementary-and-integrative-medicine
  42. Waldfogel, M. (2024, January 19). Beyond Dry January - How to Help Patients Reduce or Eliminate Alcohol Consumption. Rupa Health. https://www.rupahealth.com/post/beyond-dry-january---how-to-help-patients-reduce-or-eliminate-alcohol-consumption
  43. Weinberg, J. (2022, August 16). 34 Million Americans Have This Symptomless Bone Condition - Here’s How You Can Prevent It. Rupa Health. https://www.rupahealth.com/post/osteopenia-prevention
  44. Yoshimura, H. (2024, February 13). Exercise and Male Hormones: Functional Medicine Insights for Hormonal Optimization. Rupa Health. https://www.rupahealth.com/post/exercise-and-male-hormones-functional-medicine-insights-for-hormonal-optimization
Subscribe to the Magazine for free to keep reading!
Subscribe for free to keep reading, If you are already subscribed, enter your email address to log back in.
Thanks for subscribing!
Oops! Something went wrong while submitting the form.
Are you a healthcare practitioner?
Thanks for subscribing!
Oops! Something went wrong while submitting the form.