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Follicle Stimulating Hormone (FSH), Serum

Published: August 9, 2026Updated: August 16, 2026

This blood test measures your levels of follicle-stimulating hormone (FSH), a hormone produced by the pituitary gland that plays a key role in reproductive health.

Quick summary

["FSH helps regulate egg production in women and sperm production in men."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
47619-2
Short code
FSH 2.5h p 100 ug LRH IV SerPl-aCnc
Synonyms
FSH 2.5h p 100 ug LRH IV 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 This Test Is Done

Your doctor may order an FSH test to evaluate fertility issues, assess hormonal imbalances, or check for conditions affecting the ovaries, testes, or pituitary gland. It can also help diagnose conditions like early menopause, polycystic ovary syndrome (PCOS), or hypogonadism.

What to Expect Before the Test

No special preparation is needed for this blood test. You may be asked to fast for 8–12 hours before the draw if your doctor specifies it, but this is not always required for FSH testing alone.

What to Expect During the Test

A healthcare provider will insert a small needle into a vein in your arm. You may feel a slight pinch, but the procedure is quick and usually painless. Blood will be collected into a tube.

What the Results Mean

Results are interpreted based on your age, sex, and medical history. High or low FSH levels may indicate underlying health concerns that need further evaluation.

Reference range

Follicular: 3.5-12.5 mIU/mLN/A

Specimen: serum

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.

Elevated FSH levels can signal conditions like premature ovarian insufficiency (POI) in women or reduced fertility in men. Low FSH may suggest pituitary disorders, hypogonadism, or other hormonal deficiencies. Always discuss results with your healthcare provider for personalized guidance.

Short name

FSH Level

Frequently asked questions

What causes abnormal FSH levels?
Abnormal FSH levels can result from conditions like ovarian or testicular dysfunction, pituitary disorders, genetic factors, or certain medications. Hormonal imbalances, autoimmune diseases, or exposure to toxins may also play a role.
How often should I get an FSH test?
Your doctor will determine the frequency of FSH testing based on your symptoms, medical history, and treatment needs. Follow-up tests may be scheduled if initial results suggest further investigation is needed.
Can lifestyle changes affect FSH levels?
Yes, lifestyle factors such as stress, poor sleep, obesity, and certain medications can influence hormone levels, including FSH. Maintaining a balanced diet, regular exercise, and managing stress may support overall hormonal health.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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