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Follicle Stimulating Hormone (FSH) – Serum or Plasma

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

This blood test measures the amount of follicle-stimulating hormone (FSH) in your serum or plasma. FSH plays a key role in regulating hormone production related to reproduction, including egg and sperm development.

Quick summary

["FSH helps assess fertility, hormone balance, and potential issues in reproductive health."]

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

Key facts at a glance

LOINC
53146-7
Short code
FSH 45M p chal SerPl-aCnc
Synonyms
FSH 45M 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

Why This Test Is Done

Doctors may order an FSH test to evaluate fertility problems in both men and women. In women, it can help diagnose conditions like early menopause, polycystic ovary syndrome (PCOS), or ovulation disorders. In men, it may be checked for low testosterone or infertility. It can also be used to monitor hormone treatment or check for pituitary gland issues.

What to Expect Before the Test

No special preparation is usually needed, but your doctor may advise avoiding certain activities like strenuous exercise or smoking for 24 hours before the test. If you’re taking medications that affect hormones, let your healthcare provider know. You’ll typically have a small needle inserted into a vein in your arm for blood collection.

What the Results Mean

Results are interpreted based on your age, sex, and medical history. Higher or lower-than-expected levels can signal reproductive hormone imbalances or other health concerns. Your doctor will discuss these findings with you in the context of your overall health.

Common Conditions Linked to FSH Levels

Abnormal FSH levels can be linked to fertility challenges, hormonal disorders, or conditions affecting the pituitary gland. For example, high FSH in women may indicate premature ovarian failure, while low FSH in men could suggest hypogonadism or other reproductive system issues.

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

Short name

FSH Level

Frequently asked questions

How often will I need this test?
The frequency depends on your symptoms, medical history, and treatment plan. Your doctor may recommend retesting after a few months or if symptoms change. For example, women with PCOS might need periodic monitoring, while men may be checked periodically if they’re undergoing hormone replacement therapy.
Can lifestyle changes affect FSH levels?
Yes, certain lifestyle factors may influence FSH levels. For instance, smoking, obesity, or chronic stress can sometimes alter hormone balance. Maintaining a healthy weight, managing stress, and avoiding smoking may support normal hormone function, but this isn’t a direct test for lifestyle adjustments.
Is there any risk or discomfort with this test?
The test involves a small needle inserted into your arm, which may cause minor discomfort or bruising. Most people experience only a brief pinch. Rarely, there may be mild swelling or infection at the injection site, but these are usually minor and resolve quickly. Always follow your healthcare provider’s instructions for post-test care.
  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