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Follicle Stimulating Hormone (FSH), Serum

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

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, including egg and sperm development.

Quick summary

["FSH helps regulate fertility and hormone balance in both men and women."]

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

Key facts at a glance

LOINC
48108-5
Short code
FSH 15M pre 100 ug LRH IV SerPl-aCnc
Synonyms
FSH 15M pre 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

What Is Follicle-Stimulating Hormone (FSH)?

FSH is a critical hormone involved in reproductive processes. In women, it helps stimulate the ovaries to develop eggs, while in men, it supports sperm production. Your body releases FSH in pulses to maintain healthy hormone levels and reproductive function.

Why Might You Need This Test?

Doctors may order an FSH test to evaluate fertility issues, hormone imbalances, or conditions affecting the pituitary gland. It can also help diagnose problems like polycystic ovary syndrome (PCOS), ovarian dysfunction, or hypogonadism in both genders.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is sent to a lab where it is analyzed to measure FSH levels. No special preparation is usually needed, but fasting may be advised depending on your doctor’s instructions.

What Do Results Mean?

Results provide a snapshot of your hormone activity but should be interpreted alongside other health factors, such as age, symptoms, and medical history. High or low FSH levels may signal underlying conditions requiring 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.

Clinical Significance: FSH Levels and Health

Short name

FSH Level

Frequently asked questions

Why was my FSH test ordered?
Your doctor may have recommended this test to check for fertility problems, hormone-related conditions, or signs of pituitary gland dysfunction. Common reasons include unexplained infertility, irregular menstrual cycles (in women), or low testosterone (in men).
What are typical FSH reference ranges?
Reference ranges vary by lab and individual factors like age and sex. For women, FSH levels fluctuate throughout the menstrual cycle, so results may be compared to your cycle phase. For men, baseline levels are generally used. Always discuss your results with your healthcare provider.
Can lifestyle changes affect FSH levels?
Yes, factors like stress, diet, weight, and certain medications can influence hormone levels. Maintaining a healthy lifestyle, managing stress, and avoiding smoking may support balanced hormone function. If you suspect lifestyle changes are affecting your results, talk to your doctor.
  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