From the Guidelines
A high level of Luteinizing Hormone (LH) during menses is most likely indicative of polycystic ovary syndrome (PCOS), given the most recent and highest quality evidence from 2025 1. This condition is characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology. The elevated LH levels during menses disrupt the normal hormonal balance, leading to irregular ovulation and menstruation.
Key Considerations
- PCOS is a common endocrine disorder affecting 4-6% of women in the general population, with a higher prevalence in women with temporal lobe epilepsy 2.
- The diagnosis of PCOS is based on clinical and biochemical hyperandrogenism, ovulatory dysfunction, and polycystic ovarian morphology, as well as the exclusion of other disorders that may cause similar symptoms 2.
- Elevated LH levels during menses are a key feature of PCOS, with a study finding that women with functional hypothalamic amenorrhea (FHA) and polycystic ovarian morphology (PCOM) had higher LH levels compared to those without PCOM 1.
Implications for Management
- If you have high LH during menses, it is essential to consult with an endocrinologist or gynecologist for proper evaluation, which typically includes additional hormone tests, ultrasound imaging, and possibly MRI if a pituitary issue is suspected.
- Treatment depends on the underlying cause and your fertility goals, ranging from hormonal contraceptives to regulate cycles to specific medications targeting the primary condition.
- A comprehensive approach to management should also consider the metabolic and reproductive implications of PCOS, including insulin resistance, hyperandrogenism, and ovulatory dysfunction 1.
Important Findings
- A recent study found that women with FHA-PCOM had higher LH levels and a more PCOS-typical pattern of gonadotropin secretion in response to GnRH stimulation 1.
- The study also found that women with FHA-PCOM had higher levels of anti-Müllerian hormone (AMH) and testosterone, and lower levels of sex hormone-binding globulin (SHBG) compared to those without PCOM 1.
From the Research
High LH Levels During Menses
- A high level of Luteinizing Hormone (LH) during menses can be an indicator of various conditions, including Polycystic Ovary Syndrome (PCOS) 3, 4, 5.
- In women with PCOS, an elevated LH/FSH ratio is a common characteristic, with studies showing that around 70% of patients have an abnormal LH/FSH ratio 3.
- The LH/FSH ratio can be useful in predicting the development of a dominant follicle in women with PCOS, particularly when using letrozole for ovulation induction 4.
- High LH levels during menses can also be associated with other hormonal changes, such as increased levels of estradiol and progesterone, which can affect follicular maturation and ovulation 6, 7.
- However, it's essential to note that LH levels can vary throughout the menstrual cycle, and a single measurement may not be indicative of an underlying condition 6, 7.
Factors Influencing LH Levels
- Thyroid-stimulating hormone (TSH) levels can influence LH/FSH ratio, with studies showing a negative correlation between TSH and prolactin levels in women with PCOS 3.
- Body mass index (BMI) does not appear to be correlated with LH/FSH ratio in women with PCOS, suggesting that other factors may be more influential in determining LH levels 5.
- The relationship between LH and other hormones, such as follicle-stimulating hormone (FSH) and estradiol, plays a crucial role in regulating follicular growth and ovulation 7.