FSH (Follicle-Stimulating Hormone and Follitropin)

In women, FSH helps control the menstrual cycle and stimulates the growth of eggs in the ovaries. FSH levels in women change throughout the menstrual cycle, with the highest levels happening just before an egg is released by the ovary. This is known as ovulation. In men, FSH helps control the production of sperm.

Low FSH levels in men may mean parts of the brain (the pituitary gland or hypothalamus) do not produce normal amounts of some or all of its hormones. High FSH levels in boys or girls may mean that puberty is about to start.

High FSH levels can indicate primary ovarian insufficiency (POI), the menopausal transition, or Turner syndrome. FSH levels can also be higher in heavy smokers or drinkers or people with a vitamin D deficiency.

In women, a lack of follicle stimulating hormone leads to incomplete development at puberty and poor ovarian function (ovarian insufficiency). In this situation ovarian follicles do not grow properly and do not release an egg, thus leading to infertility.

Causes of this may include damage to the testicles (from radiation, trauma, or alcohol abuse), genetic problems, advancing age, hormonal disorders, certain medications (like pain medications or steroids), diseases such as HIV/AIDS or Type 2 diabetes, or (in rare cases) tumors of the pituitary gland.

Stress can affect your overall hormone levels including FSH specifically. In fact, one study found stress to be associated with higher than normal FSH levels. If you struggle with chronic stress, bear in mind that this can have a negative effect on your menstrual cycle, ability to get pregnant, and overall health.