FSH (Follicle Stimulating Hormone) – Serum, Quantitative
This blood test measures the amount of follicle-stimulating hormone (FSH) in your serum. FSH is a hormone produced by the pituitary gland that plays a key role in reproductive health, particularly in regulating the menstrual cycle and sperm production.
["FSH helps assess fertility, hormone balance, and potential issues with ovulation or egg development in women, or sperm production in men."]
Key facts at a glance
- LOINC
- 50481-1
- Short code
- FSH sp5 SerPl-aCnc
- Synonyms
- FSH sp5 SerPl-aCnc
- 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
Why Might You Need This Test?
Your doctor may order an FSH test to evaluate fertility problems, such as irregular menstrual cycles, difficulty becoming pregnant, or low sperm counts. It can also help diagnose conditions like premature ovarian insufficiency (POI) in women or hypogonadism in men. Sometimes, FSH levels are checked alongside other hormones like luteinizing hormone (LH) or estrogen/testosterone to get a full picture of reproductive health.
What to Expect Before the Test
No special preparation is usually needed for an FSH blood test. You may be asked to fast for 8–12 hours before the draw, but this depends on your doctor’s instructions. On the day of the test, avoid strenuous activity or caffeine, as these can sometimes affect hormone levels temporarily.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but the procedure is quick and typically painless. The blood sample is then sent to a lab for analysis.
What Do Your Results Mean?
FSH results are interpreted based on your age, sex, and medical history. High or low levels can signal underlying conditions, but your doctor will discuss the results in the context of your overall health. For example, elevated FSH in women may indicate early menopause, while elevated FSH in men could suggest low testosterone or other hormonal imbalances.
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 of FSH Levels
Short name
FSH Level
Frequently asked questions
What Causes High FSH Levels?
What Causes Low FSH Levels?
Can FSH Levels Change Over Time?
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