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Follicle Stimulating Hormone (FSH), Serum or 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 egg development in women and sperm production in men."]

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

Key facts at a glance

LOINC
27865-5
Short code
FSH sp3 p chal SerPl-aCnc
Synonyms
FSH sp3 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 critical hormone involved in reproductive function. In women, it helps stimulate the growth of follicles in the ovaries, which eventually release an egg. In men, it supports sperm production in the testes. Your body releases FSH in response to signals from other hormones, like luteinizing hormone (LH).

Why Might You Need This Test?

Doctors may order an FSH test to evaluate fertility issues, assess hormonal imbalances, or diagnose conditions like polycystic ovary syndrome (PCOS), premature ovarian insufficiency, or hypogonadism. It can also help monitor hormone therapy or check for pituitary gland disorders.

How Is the Test Performed?

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

What Do Results Mean?

FSH levels can vary based on age, sex, and reproductive stage. Higher or lower than expected levels may indicate underlying health concerns that need further evaluation by a healthcare provider.

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

How common is this test performed?
FSH testing is commonly used in fertility evaluations, hormone-related assessments, and reproductive health screenings. It is especially important for women undergoing fertility treatments or those experiencing menopause-related symptoms, as well as men with suspected low testosterone or fertility problems.
What are the typical reference ranges?
Reference ranges for FSH can vary by lab and individual factors like age and sex. Your doctor will interpret results in the context of your overall health and medical history. Exact values are not provided here due to variability.
Can lifestyle factors affect FSH levels?
Yes, lifestyle factors such as stress, poor sleep, obesity, and certain medications (e.g., birth control, antidepressants) can influence FSH levels. Maintaining a healthy lifestyle may support balanced hormone 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