Skip to content

Luteinizing Hormone (LH) in Serum or Plasma

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

This test measures the amount of luteinizing hormone (LH), a hormone produced by the pituitary gland that plays a key role in reproductive health.

Quick summary

["LH helps regulate ovulation in women and sperm production in men."]

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

Key facts at a glance

LOINC
35358-1
Short code
LHON Syn gene Mut Anl Bld/T
Synonyms
LHON Syn gene Mut Anl Bld/T
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
1.5
Ref high
9
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
molgen
CPT
83002
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Might You Need This Test?

Your doctor may order an LH test to evaluate reproductive function, diagnose hormonal imbalances, or assess conditions like infertility, menstrual irregularities, or symptoms of early menopause. It can also help monitor certain cancers or hormonal 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 your blood is drawn early in the morning. Avoid strenuous activity or caffeine on the day of testing. If you’re taking hormonal medications, let your doctor know.

What Happens During the Test?

A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but the procedure is quick and typically painless. The blood sample is sent to a lab for analysis.

What Are the Possible Results?

Results are reported in international units per liter (IU/L) or milliliters per liter (mIU/mL), depending on the lab. Your doctor will interpret the results in relation to your symptoms, medical history, and other tests.

Reference range

Follicular: 1.5-9.0 mIU/mLN/A

Specimen: whole-blood

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.

High LH levels may indicate conditions like premature menopause, polycystic ovary syndrome (PCOS), or certain cancers. Low LH levels could suggest pituitary disorders, hypothyroidism, or other hormonal deficiencies. LH is also used to monitor ovarian reserve in women undergoing fertility treatments.

Short name

LH Test

Frequently asked questions

How often will I need this test?
The frequency depends on your medical condition. Some patients need LH testing once, while others may require follow-up tests every few months or years, especially if managing chronic conditions like infertility or hormonal disorders.
What do my LH levels mean if they’re outside of my usual range?
If your LH levels are higher or lower than expected, your doctor will discuss potential causes with you. This could include lifestyle factors, underlying health conditions, or the need for further testing (like additional hormone levels or imaging).
Can lifestyle changes affect LH levels?
Yes, factors like stress, weight fluctuations, certain medications (e.g., birth control, antidepressants), and smoking can influence LH levels. Making healthy lifestyle choices—such as managing stress, maintaining a healthy weight, and avoiding tobacco—may help support hormonal balance.
  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