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Follicle Stimulating Hormone (FSH) – Serum, Quantitative

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, particularly in regulating egg development in women and sperm production in men.

Quick summary

["FSH helps balance hormone levels and supports fertility; abnormal levels may indicate reproductive health concerns."]

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

Key facts at a glance

LOINC
20433-9
Short code
FSH SerPl IRP2-aCnc
Synonyms
FSH SerPl IRP2-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
Method
nd-irp
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 healthcare provider may order an FSH test to evaluate fertility issues, assess hormonal imbalances, diagnose conditions like polycystic ovary syndrome (PCOS) in women, or check for hormonal disorders in men. It can also help monitor conditions such as ovarian reserve or testicular function.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if your blood is drawn early in the morning. Avoid strenuous exercise or smoking for a few hours before your appointment. Inform your provider about any medications you’re taking, as they may affect results.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The process is quick and typically causes only mild discomfort. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are interpreted based on your age, sex, and medical history. High or low FSH levels can signal underlying health concerns, but individual results vary. Your provider will discuss the findings in relation to your specific situation.

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 Are Common Causes of Abnormal Results?
Elevated FSH levels may occur in women with early menopause, ovarian failure, or certain genetic conditions. In men, high FSH can be linked to low testosterone or testicular disorders. Low FSH might suggest pituitary issues, hypothyroidism, or conditions affecting hormone production.
How Often Should I Get This Test?
The frequency depends on your symptoms, medical history, and treatment needs. Your provider will determine how often to repeat the test, such as during fertility evaluations, monitoring hormonal treatments, or assessing reproductive health over time.
Can Diet or Lifestyle Affect FSH Levels?
While diet and lifestyle factors like stress, weight, and smoking can influence overall hormone balance, they don’t directly alter FSH levels. However, maintaining a healthy weight and managing chronic conditions (like diabetes) may support better hormonal function.
  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