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Luteinizing Hormone (Serum) – Immunoassay

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

This blood test measures the amount of luteinizing hormone in your serum. LH is a hormone produced by the pituitary gland that plays a key role in reproductive health, including ovulation in women and sperm production in men.

Quick summary

["LH helps regulate your menstrual cycle and fertility; abnormal levels may signal reproductive issues."]

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

Key facts at a glance

LOINC
47864-4
Short code
LH 2.5h p 100 ug LRH IV SerPl-aCnc
Synonyms
LH 2.5h p 100 ug LRH IV SerPl-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
1.5
Ref high
9
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83002
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 Is This Test Done?

Your doctor may order an LH test to evaluate fertility, diagnose hormonal imbalances, or check for conditions like polycystic ovary syndrome (PCOS) in women, or low testosterone in men. It can also help monitor treatment for hormone-related disorders.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if your doctor specifies it. Wear comfortable clothing for blood draws, and arrive with an empty stomach if fasting is required.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the process usually takes just a few minutes. The blood sample is then sent to a lab for analysis.

What Does the Test Result Mean?

Results are compared to a range of normal values, which can vary slightly by lab. High LH levels may indicate conditions like ovarian hyperstimulation or early menopause in women, while low levels could suggest pituitary disorders or hormonal deficiencies.

Reference range

Follicular: 1.5-9.0 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: LH Levels and Health

Short name

Luteinizing Hormone (LH)

Frequently asked questions

What Are Common Causes of Abnormal LH Levels?
In women, elevated LH can result from conditions like PCOS, ovarian cysts, or premature ovarian insufficiency. In men, low LH may signal hypogonadism (low testosterone) or pituitary tumors. Always discuss symptoms with your doctor for personalized interpretation.
How Often Should I Get This Test?
Your doctor will determine the frequency based on your health needs. LH testing may be routine for fertility evaluations, monitoring hormonal treatments, or managing reproductive disorders. Follow-up tests could be scheduled every few months or as needed.
Can Diet or Lifestyle Affect LH Levels?
Dietary factors like high-fat or high-sugar foods may influence hormone levels indirectly, but LH testing itself does not require strict dietary restrictions unless fasting is required. Stress, sleep, and exercise can also impact hormone balance—prioritize a healthy lifestyle for overall well-being.
  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