Luteinizing Hormone (LH) in Serum or Plasma
This test measures the levels of luteinizing hormone, 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.
["LH helps trigger important reproductive processes and may be checked if fertility issues or hormonal imbalances are suspected."]
Key facts at a glance
- LOINC
- 25717-0
- Short code
- LH 1.5h p 100 ug LRH IV SerPl-aCnc
- Synonyms
- LH 1.5h 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 Might You Need This Test?
Your doctor may order an LH test if you have symptoms like irregular menstrual cycles, infertility, or signs of hormonal changes. Men might have it checked for low sperm production or related conditions. It can also be part of routine evaluations for conditions like polycystic ovary syndrome (PCOS) or thyroid disorders.
What to Expect During the Test
A blood sample will be taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The sample is then sent to a lab for analysis. You can eat and drink normally before the test unless your doctor advises otherwise.
How LH Levels Can Vary
LH levels fluctuate naturally throughout the menstrual cycle in women, peaking just before ovulation. In men, levels remain relatively steady but can change with health conditions or medications. Your results will be compared to general reference ranges provided by your lab.
Common Reasons for Testing
LH testing is often done to diagnose fertility problems, evaluate hormonal imbalances, check for conditions like hypogonadism (low sex hormone production), or monitor treatment progress for reproductive health issues.
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.
Clinical Significance: What Does LH Tell Us?
Short name
LH Test
Frequently asked questions
What are the normal LH levels?
How soon will I get my results?
Can lifestyle changes affect LH levels?
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