Released by the pituitary gland, follicle-stimulating hormone (FSH) is a gonadotropic hormone that works alongside luteinizing hormone (LH) to regulate important reproductive processes. In women in particular, FSH is known to stimulate the early development of ovarian follicles, which eventually release an egg during ovulation.
To help you better understand how this hormone works and what levels to expect throughout your menstrual cycle and beyond, take a closer lookwhat FSH iswhat it does and what is considered a “normal” FSH level. We'll also cover what it can mean when your FSH levels are too high or too low and how to get your FSH levels tested.
Although FSH is produced by both males and females, please note that this article focuses on the role that FSH plays in the female reproductive process.
What are normal FSH levels in women?
In women, FSH levels in the blood can range from as little as 0.1 mIU/ml during pregnancy to over 100 mIU/ml during menopause. Therefore, "normal" FSH levels vary depending on factors such as your age,whether you are pregnant or not, and what phase of the menstrual cycle you are in.
In women with regular menstrual cycles, FSH levels typically range from 1.4 to 9.9 mIU/mL during the first half of the menstrual cycle before rising to 17.2 mIU/mL during ovulation.
During pregnancy, FSH levels fall to ≤ 0.1 mIU/mL.
In women approaching menopause, FSH levels can vary dramatically depending on the regularity of their menstrual cycle. Once menopause is reached, FSH levels increase to over 30 mIU/ml and can even reach over 100 mIU/ml.
What is FSH?
In women, FSH stimulates premature or "primal"ovary folliclesduring the follicular phase of the menstrual cycle. This follicle contains a developing egg, and as it develops, FSH helps initiate its production of estrogen. This influx of estrogen not only helps the follicle continue to develop, but also helps thicken the lining of the uterus.
In the middle of the menstrual cycle, aIncrease in luteinizing hormone (LH)helps the follicle release the egg – which is known as ovulation. After the egg is released, the remaining cell cluster then forms theyellow body. The corpus luteum then continues to produce both estrogen and progesterone. Together, these hormones help support the implantation process and early pregnancy.
Without FSH, the early development of the ovarian follicles and corpus luteum would not be possible.
Normal FSH levels and ranges
The following ranges are based on figures from theUniversity of Rochester Medical Center. Please note that the ranges may vary slightly depending on the laboratory.
FSH levels before pregnancy
Before pregnancy, FSH levels typically range from 1.4-9.9 mIU/mL during the follicular phase and 1.1-9.2 mIU/mL during the luteal phase.
During theFollicle phase, FSH helps stimulate the development of the ovarian follicle so that it can eventually develop an egg and ovulate. During the luteal phase, FSH levels drop slightly but continue to stimulate the ovaries to produceestrogen and progesterone.
FSH levels during ovulation
During ovulation, FSH levels can range from 6.2 to 17.2 mIU/ml. At this point, both FSH andLH levelsare at their peak and this surge in hormones causes the egg to be released (ovulation).
FSH levels during pregnancy
During pregnancy, all processes related to ovulation stop and FSH levels should remain low throughout pregnancy.A studyfound that FSH levels in pregnant women fall to a maximum of 0.1 mIU/ml as early as 26-30 days after ovulation.
FSH levels in perimenopause
During the transition to menopause (perimenopause), FSH levels can fluctuate greatly. Therefore, you can see FSH levels between 1.4 mIU/ml and over 30 mIU/ml. However, if FSH levels are consistently above 30 mIU/mL, this is the caseusually assumed that menopause has been reached.
FSH levels during menopause
WhileMenopause, FSH levels can range from 19 to 100+ mIU/mL. This is because as a woman ages, the number of follicles that contain eggs at the beginning of the menstrual cycle (also called the ovarian reserve) gradually decreases.
With fewer available follicles, estrogen levels drop. Because estrogen tells the body to stop producing FSH, a drop in estrogen causes FSH levels to rise.
FSH levels by age
| Age | FSH levels |
|---|---|
| 0-11 (before puberty) | 0-4.0 mIU/ml |
| 11-14 (during puberty) | 0.3-10.0 mIU/ml |
| 14-40 (Menstruation) | 4.7-21.5 mIU/ml |
| 40+ (post menopause) | 25.8-134.8 mIU/ml |
FSH level chart
| reproductive phase | FSH levels |
|---|---|
| before puberty | 0-4.0 mIU/ml |
| during puberty | 0.3-10.0 mIU/ml |
| women who are still menstruating | 4.7-21.5 mIU/ml |
| After menopause | 25.8-134.8 mIU/ml |
The FSH level changes
What if I have high FSH levels?
If you're in your forties or fifties, high FSH levels can be a sign that you're approachingMenopause. Typically, doctors say you've reached menopause when your LH levels are consistently above 30 mIU/mL for a period of time.
In addition to high FSH levels, you may also experience otherssymptoms of menopausesuch as fatigue, mood swings, vaginal dryness and hot flashes. To treat these symptoms, your doctor may recommendhormone replacement therapy. Many doctors also recommend certain lifestyle changes, such as: Examples include trying cognitive behavioral therapy (CBT), eating a balanced diet, and regular exercise to help manage menopause symptoms.
THENis another condition that can cause FSH levels to be above average. This condition occurs in women under the age of 40 and causes the ovaries to stop working properly. Symptoms of POI include irregular menstrual periods,difficulty getting pregnant, and experiencing general menopause symptoms.
Doctors may recommend hormone replacement therapy to treat POI. If you have POI and aretry to get pregnant, you should consider fertility treatments such as in vitro fertilization (IVF).
What if I have low FSH levels?
Low FSH levels are not common and can indicate a problem with your pituitary gland. For example,Hypopituitarismusis a rare condition that prevents your body from producing enough hormones, which can lead to low FSH levels.
Symptoms of hypopituitarism include stomach pain, excessive thirst, excessive urination, fatigue, anemia, and weight fluctuations. To diagnose hypopituitarism, your doctor will want to check your hormone levels with a blood test. This may be followed by an MRI of your pituitary gland.
In addition to hypopituitarism, being underweight can also lead to disruptions in your hormones. If you're struggling to maintain a healthy weight, it's a good idea to talk to your doctor about safe weight gain strategies.
Test FSH levels
Testing your FSH levels may be necessary if you are having trouble conceivingirregular menstrual cycleor if you have missed your period and you think it may be due to menopause. In addition, it may also be necessary if you have common symptoms of pituitary disease such as fatigue, weight loss or loss of appetite.
If you need to have your FSH levels checked, here are your testing options, both at home and in the doctor's office.
It is important to note here that due to the fluctuations of FSH throughout the menstrual cycle, it is important to test for FSH at the right time. The best time to have an FSH test is day 3 of your menstrual cycle, with day 1 being the first day of your period.
At home
When it comes to testing for FSH at home, there are currently two options. The first option is to take oneFSH urine test. This type of test is very similar to a standard pregnancy test, but instead of testing for hCG (human chorionic gonadotropin), this test measures FSH. A positive test result indicates that your FSH levels are elevated above the standard menopausal threshold.
In addition to a urine test, there are also home blood tests that you can order online. These tests usually require you to take a sample of blood from your finger and then send it to a lab for testing. You will then receive the results of your exact FSH values within a few working days. Some of the most common brands of home blood tests include:LetsGetCheckedandAlways good.
Although it is currently not possible to test with FSHMira, we have plans to release FSH test sticks in the future.
At the doctor's
You can also have your FSH level tested in your doctor's office. A nurse usually draws a small amount of blood from a vein in your arm. Your doctor will then send your blood sample to an outside laboratory for testing. Within a few days, your doctor will call you to discuss your results and next steps.
While this FSH testing method is accurate, it can be expensive and difficult to perform regularly given the scheduling requirements.