FSH (Follicle-Stimulating Hormone) with Serum/Plasma Measurement
This test measures the amount of follicle-stimulating hormone (FSH) in your blood. FSH plays a key role in hormone regulation, particularly in reproductive health for both men and women.
["FSH helps manage fertility and hormone balance in the body."]
Key facts at a glance
- LOINC
- 12663-1
- Short code
- FSH 40M p chal SerPl-sCnc
- Synonyms
- FSH 40M p chal SerPl-sCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 3.5
- Ref high
- 12.5
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83001
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
The follicle-stimulating hormone (FSH) test is done to measure how much FSH is in your blood. Your doctor may order it to help evaluate fertility concerns, irregular or missed menstrual periods, symptoms of menopause, or possible problems with the pituitary gland, ovaries, or testicles.
Your healthcare provider may order an FSH test to check for hormonal imbalances, especially if you’re experiencing symptoms like irregular periods, infertility, low libido, or signs of early menopause. It can also help diagnose conditions like polycystic ovary syndrome (PCOS), hypogonadism, or Klinefelter syndrome in men.
Before the test, your doctor will tell you whether you need to pause any medicines, such as birth control pills or hormone therapy, since they can affect FSH levels. You usually do not need to fast, but timing matters: the test is often done on a specific day of the menstrual cycle, commonly day 2 through day 4. Tell your doctor about all medications and supplements you take.
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it’s drawn early in the morning. If you’re taking hormonal medications, let your provider know so they can adjust your results accordingly.
A healthcare professional will draw a small sample of blood, usually from a vein in your arm. The site is cleaned with an antiseptic, a band may be wrapped around your upper arm, and a needle is inserted to collect the blood into a tube. The sample is then sent to a laboratory, and the entire process takes only a few minutes.
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab for analysis using an immunoassay method to measure FSH levels.
High FSH levels may mean the ovaries or testicles are not working properly, that a woman is approaching or has reached menopause, or that a genetic condition is present. Low FSH levels can point to problems with the pituitary gland or hypothalamus, or may occur during pregnancy. Your doctor will interpret your results along with your symptoms, medical history, and other tests to make an accurate diagnosis.
Results are interpreted based on your age, sex, and medical history. High or low FSH levels can indicate underlying health issues, but your provider will discuss the results with you in detail.
Reference range
Follicular: 3.5-12.5 mIU/mLN/A
For females: inform if menstrual cycle status. For certain tests, timing within menstrual cycle may matter.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: FSH Levels and Health Conditions
Short name
FSH Level
Frequently asked questions
In women, elevated FSH may signal early menopause, ovarian failure, or conditions like PCOS. Low FSH could suggest hypothyroidism, pituitary disorders, or other hormonal imbalances. In men, abnormal FSH levels may point to issues like low testosterone or genetic conditions affecting fertility.
If your results are outside the expected range, your healthcare provider may recommend further testing, such as additional hormone checks or imaging studies, to identify the cause. They’ll work with you to create a treatment plan if needed, such as hormone therapy or lifestyle adjustments.
Yes, factors like stress, poor sleep, obesity, and certain medications can influence FSH levels. Maintaining a healthy lifestyle—such as regular exercise, a balanced diet, and stress management—may help support normal hormone function.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy