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FSH (Follicle Stimulating Hormone) with Serum/Plasma Specimen, Immunoassay Method

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

This test measures the levels of Follicle Stimulating Hormone (FSH) in your blood. FSH plays a key role in hormone regulation, particularly in reproductive health.

Quick summary

["FSH helps manage 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
27870-5
Short code
FSH sp4 p chal SerPl-aCnc
Synonyms
FSH sp4 p chal 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 hormone produced by the pituitary gland that stimulates the growth of follicles in the ovaries (in women) and sperm production in the testes (in men). It works alongside other hormones like luteinizing hormone (LH) to support reproductive function.

Why Might Your Doctor Order This Test?

Doctors may order an FSH test to evaluate fertility issues, assess hormone imbalances, diagnose conditions like polycystic ovary syndrome (PCOS), or check for hormonal disorders in both men and women.

Common Reasons for Testing

In women, FSH levels can help determine ovarian reserve (the number of eggs remaining) or check for conditions like premature ovarian failure. In men, it may be used to assess low testosterone or infertility.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The sample is sent to a lab for analysis using an immunoassay method to measure FSH levels accurately.

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.

◆Associated findings1

Short name

FSH (Serum/Plasma)

Frequently asked questions

How long does it take to get results?
Test results typically take 1–3 business days to be processed and returned to your healthcare provider. Results may vary depending on the lab and your healthcare provider’s workflow.
What do abnormal FSH levels mean?
High FSH levels may indicate low ovarian reserve in women or low testosterone in men. Low FSH levels could suggest pituitary gland issues or other hormonal imbalances that need further evaluation.
Can lifestyle changes affect FSH levels?
Yes, factors like stress, weight fluctuations, certain medications (e.g., birth control, thyroid medications), and chronic illnesses can influence FSH levels. Discuss any changes with 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