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Luteinizing Hormone (LH) – Serum, Mass Concentration

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 ovulation in women and sperm production in men.

Quick summary

["LH helps regulate your menstrual cycle and fertility."]

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

Key facts at a glance

LOINC
1596-6
Short code
LH 30M p GnRH SerPl-mCnc
Synonyms
LH 30M p GnRH SerPl-mCnc
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 check for hormonal imbalances, evaluate fertility issues, diagnose conditions like polycystic ovary syndrome (PCOS), or monitor treatment for hormone-related disorders. It can also help assess pituitary gland function or screen for conditions affecting hormone production.

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 it involves drawing blood from your arm. If you’re taking medications that affect hormones, let your provider know. For some fertility-related tests, timing may depend on your menstrual cycle.

What Happens During the Test?

A healthcare professional will insert a small needle into a vein in your arm to draw blood. You may feel a brief pinch, but it’s usually over quickly. The blood sample is then sent to a lab for analysis. The test typically takes about 10–15 minutes.

What Are the Possible Results?

Results are reported in units of mass concentration (typically IU/mL). Your provider will interpret the results in relation to your symptoms, medical history, and other tests. Abnormal levels may indicate conditions affecting hormone production or reproductive health.

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 Test

Frequently asked questions

How long does it take to get LH test results?
Results are usually available within 1–3 business days, depending on your lab and healthcare provider. Some labs may provide preliminary results sooner, but your doctor will discuss the full interpretation with you.
Can LH levels change with the menstrual cycle?
Yes, LH levels fluctuate naturally. In women, LH peaks around the midpoint of the menstrual cycle (day 12–14) to trigger ovulation. If your test is for fertility evaluation, timing may be critical—your provider will advise you on the best window for testing.
What conditions might require repeated LH testing?
Repeated LH testing may be needed if you have ongoing fertility issues, unexplained menstrual irregularities, or symptoms of hormonal disorders like PCOS. Your doctor might also retest after starting hormone treatments or if symptoms worsen.
  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