From the FDA Drug Label
Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these gonadotropins seen in postmenopausal women.
The effects of menopause on Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH) levels are an increase in their levels, as estrogens, which normally modulate their secretion through a negative feedback mechanism, are decreased in postmenopausal women. Estrogens act to reduce the elevated levels of LH and FSH seen in postmenopausal women 1.
From the Research
During menopause, FSH and LH levels significantly increase due to the decline in ovarian function and estrogen production, which removes the negative feedback mechanism that normally keeps these hormones in check, as supported by the most recent study 2. This increase in FSH and LH levels is a hallmark laboratory finding of menopause and can be used diagnostically in women over 45 with menopausal symptoms. The hormonal shift happens because the pituitary gland attempts to stimulate the failing ovaries by producing more FSH and LH. However, the ovaries become increasingly resistant to this stimulation as follicle numbers diminish.
Some key points to consider:
- FSH typically rises first and more dramatically, often exceeding 40 mIU/mL, while LH increases to a lesser extent 3, 4, 5.
- The decline in inhibin B levels, which reflects the fall in ovarian follicle numbers, contributes to the increase in FSH levels 3, 5.
- Estradiol levels remain relatively unchanged or tend to rise with age until the onset of the transition, but then decrease significantly in the late perimenopause 3, 4.
- The hormonal imbalance contributes to many menopausal symptoms, including hot flashes, mood changes, and vaginal dryness, and can be alleviated with hormone replacement therapy, which helps reduce these symptoms by partially restoring the negative feedback loop and lowering FSH and LH levels toward premenopausal ranges 6.
It's worth noting that the effects of menopause on FSH and LH levels can have significant implications for women's health, including an increased risk of osteoporosis and cardiovascular disease, as suggested by recent studies 2. Therefore, it's essential to consider these factors when managing menopausal symptoms and preventing long-term health consequences.