Key takeaways
- Typical levels of follicle-stimulating hormone (FSH) can vary by age, sex, and the phase of the menstrual cycle. For example, in the follicular phase, it can range from 1 to 9 international units per liter (IU/L).
- Hormonal disruption and other factors can lead to high or low levels. However, many factors can affect FSH levels, including a person’s weight and various health issues.
- Doctors will usually use a blood test to analyze a person’s FSH levels, although in some cases, a urine test may be possible. Female FSH testing may require taking measurements throughout the menstrual cycle.
Follicle-stimulating hormone (FSH) plays an integral role in reproductive processes. Doctors can test FSH levels to assess fertility, among other things.
FSH helps mature the ovarian follicles that release eggs, called ova. Without the release of FSH, the reproductive cycle cannot continue, as the ovaries will not release an egg. FSH also supports the growth and development of sperm.
Doctors can check FSH levels using a blood test to assess fertility or see if a person is going through menopause. They typically do this alongside tests for other sex hormones, such as testosterone or estrogen.
This article explores what FSH levels are and how FSH tests relate to menopause and fertility.
The use of binary terms such as “male” and “female” or “men” and “women” in this article reflects the language of the sources we’ve used. Unless otherwise noted, it’s unclear whether the research we reference included participants with expansive gender identities.
Doctors order blood tests to measure FSH levels in terms of international units per liter (IU/L).
Female FSH ranges
A person’s FSH level changes throughout their life. Below is one set of guideline ranges for female FSH levels at different life stages.
These ranges may vary depending on what exact tests a laboratory runs.
| Life stage | Normal FSH levels |
|---|---|
| before puberty | 0 to 4 IU/L |
| during puberty | 0.3 to 10 IU/L |
| while still menstruating | 4.5 to 21.5 IU/L |
| after menopause | 25.8 to 134.8 IU/L |
If FSH levels are 30 IU/L or higher and the person has not had a period for a year, they have likely reached menopause. However, doctors do not require tests to diagnose menopause. They can usually diagnose menopause using a person’s medical history and symptoms.
A menstruating person’s typical FSH levels will vary throughout the stages of the menstrual cycle.
| Menstrual cycle stage | Normal FSH levels |
|---|---|
| follicular | 3.9 to 8.8 IU/L |
| ovulatory phase | 4.5 to 22.5 IU/L |
| luteal | 1.8 to 5.1 IU/L |
During the early stages of pregnancy, 26 to 30 days after ovulation, a person’s FSH levels drop to around 0.1 IU/L.
Male FSH ranges
A person’s FSH levels will change throughout the course of their life. Below are one United States medical institution’s typical male FSH ranges. Other institutions may have different ranges.
| Age | FSH range |
|---|---|
| before puberty | 0 to 5 IU/L |
| during puberty | 0.3 to 10 IU/L |
| adulthood | 1.5 to 12.4 IU/L |
These ranges can vary between laboratories and studies. For example, an older
Further tests
When testing for female fertility, a doctor may also ask a person to track their temperature, as this
Similarly, they may order imaging scans to check the fallopian tubes. The egg cannot travel to the uterus for implantation if anything blocks the tubes.
If a person is experiencing irregular periods around the age of menopause, doctors may test for other hormone levels, including thyroid-stimulating hormone and prolactin, to help guide diagnosis.
Elevated female FSH levels may be a sign of menopause, which can cause symptoms including:
A condition called ovarian hyperstimulation syndrome (OHSS) can cause high FSH levels. It is thought to be related to cystic enlargement of the ovaries with fluid leakage from the ovaries. OHSS is rare in the absence of fertility treatments.
Doctors will regularly monitor people undergoing these treatments for any signs of OHSS.
Symptoms of OHSS include enlarged ovaries and the accumulation of fluid in the abdomen, leading to pelvic pain.
Health conditions with links to high levels of FSH
Besides menopause and OHSS, high female FSH levels have links to:
- polycystic ovary syndrome (PCOS)
- primary ovarian insufficiency (POI)
- ovarian tumor
- thyroid or adrenal gland conditions
- improper development of the ovaries
- Turner syndrome, a chromosomal disorder
High male FSH has links to:
- mumps
- a germ cell tumor
- Klinefelter syndrome, a chromosomal disease
Regardless of sex, high FSH level also shares links with radiation therapy, chemotherapy, and certain autoimmune diseases.
In children, low levels of FSH may be a sign of delayed puberty. Symptoms of low FSH levels include:
- limited sperm production
- infertility
- delays in sexual development
Low FSH levels in adults may indicate a problem with the pituitary gland or hypothalamus, which can affect FSH production.
Low female FSH also shares links with being underweight or extreme exercise.
Doctors may order the FSH test as part of a range of tests. There are various reasons to carry out the FSH test, including:
- Menopause testing: If a person’s menstrual cycle has become irregular or they have not had a period at all, a doctor may order the test. If FSH levels are high, it could indicate menopause.
- Female fertility testing: If a person is not ovulating, their FSH levels might be high or low, depending on the cause.
- Male fertility testing: FSH stimulates the growth of sperm cells. If a person’s FSH levels are high, it can mean their testicles are not functioning properly.
In addition to testing for fertility and menopause, doctors may order an FSH test to look for a pituitary disorder or determine if a child is entering puberty too early or too late.
The
An FSH test usually consists of a simple blood test. A small sample of blood is necessary, and the risks are minimal. Afterward, a person can generally return to their everyday activities.
A doctor will not use the FSH test alone to determine if a person is going through menopause or identify reasons for infertility.
One downside of hormone testing is that a person’s hormones fluctuate over hours and days. So, taking a blood sample and testing it for hormones provides only a “snapshot” of their levels. As a result, many doctors will ask people to take an FSH test on
Certain medications may also affect FSH levels. To prevent false readings, it is important for people to tell their doctor about any medications or herbal supplements they are taking.
Medications that decrease FSH levels include:
- hormone replacement therapies
- oral contraceptives
- phenothiazines
FSH tests can help a doctor evaluate fertility or menopause status.
A doctor may recommend taking several blood samples from a menstruating person throughout their menstrual cycle to assess the consistency of their FSH levels.
However, most people going through menopause will not require FSH testing.
In those
- irregular periods
- hot flashes
- mood changes
- difficulty sleeping
- vaginal dryness
For people under this age, FSH tests may be a helpful diagnostic tool for assessing fertility concerns or early menopause.
FSH plays an essential role in reproductive health. High levels of female FSH can indicate menopause, PCOS, or other health conditions. High male FSH shares links with tumors and mumps.
If FSH levels are too high in children, it can indicate a delay in puberty. In adults, low FSH can signal an issue with the pituitary gland or hypothalamus, affecting the hormone’s production.
FSH testing typically uses a blood test. People can speak with their healthcare professional about whether this test is necessary as part of their diagnosis.