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Luteinizing Hormone (Serum) – Quantitative

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

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

Quick summary

["LH levels help assess reproductive function and potential hormonal imbalances."]

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

Key facts at a glance

LOINC
56494-8
Short code
LH 2h p chal SerPl-aCnc
Synonyms
LH 2h p chal 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 healthcare provider may order an LH test to evaluate conditions affecting fertility, such as irregular menstrual cycles in women or low sperm production in men. It can also help diagnose hormonal disorders, including those related to the thyroid, adrenal glands, or pituitary gland. Additionally, LH testing may be part of a broader evaluation for symptoms like early puberty, delayed puberty, or unexplained infertility.

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 it’s part of a more complex evaluation (e.g., hormone panels). On the day of the test, avoid smoking and limit caffeine intake. If you’re taking medications that affect hormones, inform your provider.

How the Test Works

A blood sample is drawn from a vein in your arm. The serum (liquid part of blood after clotting) is then analyzed to measure LH levels using an immunoassay method, which detects the hormone’s presence and concentration.

What the Results Mean

Results are typically reported in international units per liter (IU/L). Higher or lower-than-expected LH levels may signal underlying health concerns, such as pituitary disorders, ovarian or testicular issues, or other endocrine imbalances. Your provider will interpret results in the context of your symptoms and medical history.

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.

◆Associated findings1

Short name

LH Test

Frequently asked questions

What Does an Abnormal LH Level Indicate?
Elevated LH levels may suggest conditions like premature ovarian insufficiency (in women), testicular dysfunction (in men), or certain pituitary tumors. Low LH levels could indicate hypogonadism, pituitary disorders, or conditions affecting hormone production, such as Klinefelter syndrome (in men) or primary ovarian failure (in women). Always discuss results with your healthcare provider for personalized guidance.
How Often Should I Get This Test?
The frequency of LH testing depends on your medical needs. Some patients may need it annually or as part of routine fertility evaluations, while others may require it only during specific medical evaluations (e.g., for suspected hormonal imbalances). Follow your provider’s recommendations.
Can LH Levels Change Over Time?
Yes, LH levels can fluctuate due to age, hormonal cycles (in women), medications, stress, or underlying health conditions. For example, LH spikes during ovulation in women and may vary with age-related hormonal shifts. Regular monitoring may be needed if you have a history of reproductive issues or hormonal disorders.
  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