Follicle-stimulating Hormone (FSH) & Luteinizing Hormone (LH)

What are FSH and LH?

Every woman goes through what is referred to as follicular loss. This is a life happening that is progressive; and, is marked by the loss of follicles in the ovaries. These oocytes begin diminishing in number while the baby girl is still a fetus in the womb. As soon as the women enters the menopausal stage, follicles loss start accelerating exponentially. According to a study published at the Human Reproductive Journal, when a woman advances in age, the structure and functionality of her oocytes begin deteriorating. Accompanying the changes in follicles comes the hormonal changes that happen on a monthly basis. This cardinal change of hormonal levels have an effect on the follicular loss.

FSH and LH are two hormones that play an essential role inour reproductive health. They both stimulate the gonads: a woman’s ovaries and a man’s testes, which is the reason why they are called gonadotropins. Secreted in the anterior pituitary gland, they originate from cells called the gonadotrophs. FSH and LH are glycoproteins that are made of alpha and beta subunits. Alpha parts are identical in both hormones, while the beta particles are unique to each hormone and helps it bind to the corresponding receptor.

The LH, otherwise known as Luteinizing Hormone, stimulates the gonads to produce sex steroids. It bonds to the receptors of the Leydig cells and stimulates the production of testosterone. In women, mature follicles are released as a respond to the exponential increase of the LH hormone. This is called the preovulatory LH surge that is accompanied by the proliferation of the corpora lutea from the residual cells of the ovulated follicles. LH helps the development and proper functioning of the corpora lutea. This hormone gained its name Luteinizing Hormone because it brings the luteinization of the ovarian follicles.

The FSH helps the maturation of ovarian follicles. It plays a major role in the reproductive system as it helps the production of estrogen and progesterone, which are two major hormones needed to have a proper menstrual cycle. For men, FSH helps develop the gonads, and the production of sperm.

Why take the FSH & LH test?

Both FSH and LH tests are a great tool to evaluate fertility problems, reproductive organs’ functions, as well as the pituitary problems. In addition, the LH test can detect the release of an egg from the ovaries.

You need to do the FSH test to diagnose the onset of menopause, the presence of ovarian cysts, infertility, or if you have been having an abnormal menstrual or vaginal bleeding. For men, this test can help diagnose infertility (that may result in low sperm count), as well as the root cause for the absence of testicles or have them underdeveloped. Sometimes, the FSH test is ordered for children who start having sexual features at a young age or those who end up having a delayed puberty.

The LH test is important to identify the causes of infertility; and, to help diagnose pituitary and hypothalamic disorders as well as dysfunctions of the ovaries and testicles. Getting tested for both FSH and LH can help differentiate whether your abnormal hormonal levels are caused by a true disease or they are the result of benign symptoms.

What causes the levels of FSH and LH to rise?

Some drugs and medications can have an effect on LH and FSH levels. Cimetidine, clomiphene, digitalis and levodopa pills can lead to higher levels of FSH, while oral contraceptives, phenothiazines and hormone treatments can lower the levels of this hormone. Anticonvulsants, clomiphene, and naloxone increase the levels of LH, while digoxin, oral contraceptives and hormone treatment may lower them.

You may also want to share with your doctor if you have some existing medical conditions like untreated thyroid problems, sex-dependent hormone tumors, ovarian cysts and vaginal bleeding that is uncommon.

What do your FHS and LH test results mean?

When you take a test, it may be tough to understand what it means. Your doctor can discuss with you what your levels may indicate about your health and wellbeing. Here is a guide about what you should expect. Both LH and FSH levels are different between genders and women’s age groups. Women who still have their periods have different values than menopausal women.

For the LH, pregnant women have their normal ranges below 1.5 IU/L. Women who still have their periods have their normal values as follows: during the follicular phase of their menstruation, values need to be between 1.9 and 12.5 IU/L; during the luteal phase of their menstrual cycle, values should be between 0.5 and 16.9 IU/L; finally, LH values have to be between 8.7 and 76.3 IU/L at the peak of menstruation. For women who are using oral contraceptives, LH values have to be between 0.7 and 5.6 IU/L. Finally, for women that are post-menopausal, their LH values need to be between 15.9 and 54.0 IU/L. In men, on the other hand, normal LH values should be between 0.7 and 7.9 IU/L for those between the ages of 20 and 70; and, between 3.1 and 34.0 for men above the age of 70 years.

Low levels of LH in men can lead to low testosterone levels, which could lead to sexual dysfunction, lack of libido and fatigue. In women, low levels can be the result of secondary ovarian failure that is caused by malfunctions in some parts of the brain that may lead to low levels of the hormone.

High LH levels may indicate primary ovarian failure in women, which could be caused by ovaries that are nor properly developed, genetic abnormalities, radiation exposure, autoimmune diseases, ovarian tumors, polycystic ovary syndrome, as well as adrenal or thyroid diseases. High levels in men may be caused by primary testicular failure that could be linked to chromosomal abnormalities, gonad development failure, viral infections like mumps, autoimmune disorders, germ cell tumors and trauma. Women and men who get exposed to radiation might also have high levels of LH.

For FSH, normal values are different for men and women. Men’s normal FSH values have to be between 0 and 5.0 IU/L before puberty, between 0.3 and 10.0 IU/L during puberty and between 1.5 and 12.4 IU/L in adulthood. For women, normal FSH values are set to be between 0 and 4.0 IU/L before puberty, between 0.3 and 10.0 IU/L during puberty, between 4.7 and 21.5 IU/L for women who still menstruate, and finally between 25.8 and 134.8 IU/L after menopause.

High FSH levels can indicate different ailments and malfunctions in both genders. Women who have high FSH levels may be undergoing menopause or already at it, including premature menopause. High levels can also indicate that a woman is receiving hormone therapy, that she has Turner syndrome, or that she may have a tumor (such as tumor of the pituitary gland). Men, on the other hand, may have high FSH levels when the testicles are not properly functioning. This could be the result of advanced aging that is referred to as male menopause. It could also be the result of gene problems, undergoing hormonal treatment, as well as tumors in the pituitary gland. Some factors can lead to testicular damages, such as radiation, alcoholism and chemotherapy.

Low FSH levels are caused by different factors in both genders. For women, FSH levels are low due to low weight or having had a rapid weigh loss, not ovulating, being pregnant or having malfunctions in the pituitary glands and hypothalamus. In men, low levels indicate that either the pituitary gland or the hypothalamus is not producing enough hormones needed for the proper functioning of the body.

Where can I get an FSH and LH test near me?

Please use our Lab Locator to find find a convenient testing location.

Women who have a 28-day cycle, blood should be drawn on day 21 (day 1 is the day that bleeding begins). For longer or shorter cycles, count 8 days back from the day your next menstruation would start. Women who no longer have a menstruation cycle, blood can be drawn any day of the month.

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: Sep 16, 2022