Luteinizing Hormone (LH) in Serum/Plasma
This test measures the amount of luteinizing hormone, a hormone produced by the pituitary gland, in your blood. LH plays a key role in reproductive health, particularly in regulating ovulation and sperm production.
["LH helps trigger ovulation in women and supports testosterone production in men."]
Key facts at a glance
- LOINC
- 56495-5
- Short code
- LH 3h p chal SerPl-aCnc
- Synonyms
- LH 3h 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 This Test Might Be Ordered
Your healthcare provider may recommend an LH test to evaluate reproductive function, diagnose hormonal imbalances, or monitor conditions like polycystic ovary syndrome (PCOS), infertility, or thyroid disorders. It may also be used in preconception planning or during fertility treatments.
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 blood is drawn early in the morning. Avoid strenuous activity or excessive stress on the day of testing. If you’re taking hormonal medications, let your provider know.
During the Test Process
A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are interpreted based on your sex, age, and medical history. In women, LH levels fluctuate throughout the menstrual cycle, peaking around ovulation. In men, LH supports testosterone production. Abnormal levels may indicate hormonal deficiencies or disorders.
Reference range
Follicular: 1.5-9.0 mIU/mLN/A
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 Level
Frequently asked questions
LH is critical for reproductive health. Low levels may suggest pituitary gland issues, ovarian dysfunction (in women), or hypogonadism (in men). High levels could indicate conditions like precocious puberty, tumors, or certain thyroid disorders. Always discuss results with your provider for personalized guidance.
LH is a hormone that triggers ovulation in women and stimulates testosterone production in men. It’s part of the body’s feedback system that helps regulate reproductive cycles.
LH testing is typically done as part of a routine checkup, fertility evaluation, or when symptoms suggest hormonal imbalances. Your provider will determine the best timing based on your health needs.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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