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Luteinizing Hormone (LH) in Serum or Plasma

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

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

Quick summary

["LH helps trigger important reproductive processes and may be checked for fertility issues or hormonal imbalances."]

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

Key facts at a glance

LOINC
10501-5
Short code
LH SerPl-aCnc
Synonyms
LH 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 reproductive health, diagnose conditions like polycystic ovary syndrome (PCOS), assess fertility, or check for hormonal imbalances. It can also be used to monitor treatment for conditions affecting hormone levels.

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 blood draw if your test involves a specific timing (e.g., early morning samples). Wear comfortable clothing and plan to rest for a short time afterward.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.

What Are Possible Results?

Results are typically reported in international units per liter (IU/L). Interpretation depends on your sex, age, and medical history. High or low LH levels may indicate underlying health concerns that need further evaluation.

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 Level

Frequently asked questions

What Does an LH Test Tell Me About My Health?
An LH test helps identify whether your hormone levels are within a typical range for your age and sex. It can uncover issues like infertility, hormonal imbalances, or conditions affecting reproductive health that may require medical attention.
How Often Should I Get an LH Test?
The frequency depends on your symptoms, medical history, and healthcare provider’s recommendations. Some people get LH tests as part of routine fertility evaluations, while others may need them periodically if they experience recurring menstrual issues or other reproductive concerns.
Can LH Levels Change Based on My Diet or Activity?
Yes, lifestyle factors like stress, diet, and exercise can influence hormone levels, including LH. Avoiding extreme stress, maintaining a balanced diet, and getting regular sleep may help support stable hormone function, though LH results are best interpreted in the context of clinical evaluation.
  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