Luteinising Hormone

Luteinising Hormone (LH) is a hormone produced by the anterior pituitary gland. It is crucial for reproductive health, particularly in women. LH works in tandem with Follicle-Stimulating Hormone (FSH) to regulate the menstrual cycle and ovulation. During the menstrual cycle, LH levels surge mid-cycle, triggering the release of a mature egg from the ovary, a process known as ovulation. This LH surge is a key indicator of fertility and is often measured in ovulation prediction kits. Additionally, LH stimulates the production of progesterone by the corpus luteum, which is essential for maintaining the early stages of pregnancy.

LH levels normally change across different phases of the menstrual cycle and during perimenopause. The reference ranges below help interpret your LH result based on which phase of your cycle your blood test was taken.

LH reference ranges in IU/L:

Follicular phase: 1 - 10

Mid-cycle (ovulatory phase): >10

Luteal phase: 1 - 10

Perimenopausal: <20

LH is vital for several physiological processes and reproductive health. Its primary role is to trigger ovulation, which is essential for conception. Abnormal LH levels can indicate various health issues. Elevated LH levels may suggest conditions such as polycystic ovary syndrome (PCOS), where the balance between LH and FSH is disrupted, leading to irregular ovulation and infertility. Conversely, low LH levels can be indicative of hypogonadotropic hypogonadism, a condition where the pituitary gland does not produce sufficient gonadotropins, leading to anovulation and infertility. Monitoring LH levels is also crucial in assisted reproductive technologies (ART) like in vitro fertilization (IVF), where precise timing of ovulation is necessary for successful egg retrieval and fertilization. Furthermore, LH levels can provide insights into the overall function of the hypothalamic-pituitary-gonadal axis, which is essential for diagnosing and managing various endocrine disorders.

LH levels can fluctuate due to several factors:

• Dietary Factors: Nutritional deficiencies, particularly in essential fatty acids and proteins, can impact hormone production. For example, low-fat diets may reduce cholesterol levels, a precursor for steroid hormone synthesis, potentially affecting LH levels.

• Lifestyle Factors: Stress, excessive physical activity, and significant weight changes can alter LH secretion. Chronic stress can disrupt the hypothalamic-pituitary-adrenal axis, leading to altered gonadotropin release.

• Related Biomarkers: Hormones such as oestradiol and progesterone have feedback mechanisms that regulate LH secretion. Elevated oestradiol levels typically suppress LH, while low levels can lead to increased LH secretion.

• Micronutrient Impacts: Deficiencies in vitamins and minerals like zinc, magnesium, and vitamin D can affect LH levels. Zinc is particularly important for the synthesis and release of gonadotropins.

• Environmental Influences: Exposure to endocrine-disrupting chemicals (EDCs) such as bisphenol A (BPA) and phthalates can interfere with hormone regulation, potentially affecting LH levels.[1][6][8]

Your results are high:

• Diet: Consider a balanced diet rich in essential fatty acids, proteins, and micronutrients like zinc and magnesium.

• Lifestyle:

  • Manage stress through relaxation techniques such as yoga or meditation.

  • Maintain a healthy weight and avoid excessive physical activity.

• Supplements: Zinc and magnesium supplements may help regulate hormone levels.

• Additional Tests:

  • Evaluate for PCOS

  • thyroid function tests

  • adrenal function tests to identify underlying causes of elevated LH

Your results are low:

• Diet: Ensure adequate intake of healthy fats and proteins to support hormone synthesis.

• Lifestyle: Address potential stressors and consider moderate exercise to support overall endocrine function.

• Supplements: Vitamin D and omega-3 fatty acids may support hormone balance.

• Additional Tests:

  • Assess for hypogonadotropic hypogonadism

  • pituitary function tests

  • evaluate for potential hypothalamic or pituitary disorders

1. Luteinizing hormone (LH) levels test. National Library of Medicine (MedlinePlus).

2. Przygrodzka, E., Plewes, M. R., & Davis, J. S. (2021). Luteinizing hormone regulation of inter-organelle communication and fate of the corpus luteum. International Journal of Molecular Sciences, 22(18), 9972. https://doi.org/10.3390/ijms22189972

3. Longo, M., Liuzzi, F., De Carlini, S., & La Marca, A. (2025). The role of LH in follicle development: From physiology to new clinical implications. Reproductive Biology and Endocrinology, 23(Suppl 1), 22. https://doi.org/10.1186/s12958-025-01353-8

4. Guo, L., Zhao, B., Peng, Z., et al. (2025). Nonlinear association of serum luteinizing hormone on hCG trigger day with cumulative live birth in IVF cycles: Secondary analysis of a randomized clinical trial. Journal of Assisted Reproduction and Genetics. https://doi.org/10.1007/s10815-025-03773-2

5. Santoro, N., & Polotsky, A. J. (2025). Infertility evaluation and treatment. The New England Journal of Medicine, 392(11), 1111–1119. https://doi.org/10.1056/NEJMcp2311150

6. Licinio, J., Negrão, A. B., Mantzoros, C., et al. (1998). Synchronicity of frequently sampled, 24-h concentrations of circulating leptin, luteinizing hormone, and estradiol in healthy women. Proceedings of the National Academy of Sciences of the United States of America, 95(5), 2541–2546. https://doi.org/10.1073/pnas.95.5.2541

7. Sollenberger, M. J., Carlsen, E. C., Johnson, M. L., Veldhuis, J. D., & Evans, W. S. (1990). Specific physiological regulation of luteinizing hormone secretory events throughout the human menstrual cycle: New insights into the pulsatile mode of gonadotropin release. Journal of Neuroendocrinology, 2(6), 845–852. https://doi.org/10.1111/j.1365-2826.1990.tb00650.x

8. Park, S. R., Kim, S. K., Kim, S. R., et al. (2022). Novel roles of luteinizing hormone (LH) in tissue regeneration-associated functions in endometrial stem cells. Cell Death & Disease, 13(7), 605. https://doi.org/10.1038/s41419-022-05054-7