Luteinizing Hormone (LH) in Serum/Plasma
This test measures the amount of luteinizing hormone (LH), a hormone produced by the pituitary gland that plays a key role in reproductive health.
["LH helps trigger ovulation in women and sperm production in men."]
Key facts at a glance
- LOINC
- 47687-9
- Short code
- LH 15M p 100 ug LRH IV SerPl-aCnc
- Synonyms
- LH 15M 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 healthcare provider may order an LH test to evaluate fertility issues, check for hormonal imbalances, monitor conditions like polycystic ovary syndrome (PCOS), or diagnose problems with the pituitary gland or ovaries/testes. It can also be used during pregnancy to assess early pregnancy hormone levels or in men to check for low testosterone.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw blood. If you’re taking certain medications that affect hormones, let your provider know. For some conditions (like pregnancy), timing may be important, so follow your provider’s instructions.
What Happens During the Test?
A healthcare professional will clean your arm, insert a needle into a vein, and collect a small amount of blood. The blood is then sent to a lab for analysis. The process usually takes a few minutes. You may feel a brief pinch, but most people tolerate it well.
What Are Possible Results?
Results are reported in international units per liter (IU/L). Higher or lower than expected levels may indicate underlying health concerns, so always discuss your results with your provider.
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 This Test Tell Us?
Short name
Luteinizing Hormone (Serum/Plasma)
Frequently asked questions
What Are Common Causes of Abnormal Results?
How Often Should I Get This Test?
Can I Eat or Drink Before This Test?
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