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Follicle Stimulating Hormone (FSH) in Serum/Plasma

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

This test measures the amount of Follicle Stimulating Hormone (FSH) in your blood. FSH is a hormone produced by the pituitary gland that plays a key role in reproductive health.

Quick summary

["FSH helps regulate the production of eggs in women and sperm in men."]

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

Key facts at a glance

LOINC
12664-9
Short code
FSH sp2 p chal SerPl-sCnc
Synonyms
FSH sp2 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

Why Might You Need This Test?

Your doctor may order an FSH test to check for hormonal imbalances, evaluate fertility issues, diagnose conditions like polycystic ovary syndrome (PCOS) in women, or assess hormonal disorders in men. It can also help monitor conditions like premature ovarian insufficiency or hypogonadism.

What Does the Test Involve?

You’ll provide a blood sample, usually drawn from a vein in your arm. The sample is sent to a lab where it is analyzed to measure FSH levels. The test is typically done in the morning for consistency.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to avoid certain medications or activities that could affect results. If you’re taking hormonal treatments, let your doctor know.

What Are Common Results Used For?

Results help determine if your hormone levels are within a healthy range. High or low FSH levels can signal potential reproductive or endocrine system issues that may require further evaluation or treatment.

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 Level

Frequently asked questions

What does an abnormal FSH level mean?
An abnormal FSH level may suggest issues with your reproductive system or hormone production. For example, high FSH in women might indicate problems with egg production, while high levels in men could point to reduced sperm production. Your doctor will discuss these findings with you and may recommend additional tests or treatments.
How often should I get this test?
The frequency of FSH testing depends on your medical condition and symptoms. Some people may need this test once, while others, like those with fertility issues or hormonal disorders, may require it periodically. Follow your doctor’s advice on how often to get tested.
Can lifestyle changes affect FSH levels?
Yes, lifestyle factors such as diet, exercise, stress, and smoking can influence hormone levels, including FSH. Maintaining a healthy weight, managing stress, and avoiding smoking may support balanced hormone function. Always discuss lifestyle changes with your healthcare provider before making significant adjustments.
  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