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Luteinizing Hormone (Serum) – Quantitative

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

This blood test measures the amount of luteinizing hormone (LH) in your serum. 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
12673-0
Short code
LH 3h p chal SerPl-sCnc
Synonyms
LH 3h p chal SerPl-sCnc
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

What Does LH Measure?

LH is primarily involved in triggering ovulation in women and stimulating testosterone production in men. In women, it peaks just before ovulation, which helps determine the timing of the menstrual cycle. In men, it supports the production of sperm.

Why Might You Need This Test?

Doctors may order an LH test to evaluate reproductive function, diagnose hormonal imbalances, or assess conditions like infertility, irregular periods, or low testosterone levels. It can also help monitor conditions such as polycystic ovary syndrome (PCOS) or pituitary disorders.

How Is the Test Performed?

A blood sample is drawn from a vein in your arm. The serum (liquid part of blood after clotting) is then tested in a lab using an immunoassay method to measure LH levels.

What Do LH Levels Tell You?

Higher-than-normal LH levels may indicate conditions like early puberty, ovarian dysfunction, or certain tumors. Lower-than-normal levels could suggest pituitary issues, hypogonadism, or thyroid problems. However, individual results depend on your age, sex, and overall 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 often should I get an LH test?
The frequency depends on your medical reason for testing. If you're being monitored for a known condition like infertility or hormonal imbalance, your doctor may recommend testing at specific intervals (e.g., monthly, every few months). If you're asymptomatic, LH testing is usually not routine unless symptoms suggest hormonal issues.
What are typical LH reference ranges?
Reference ranges vary by lab and individual factors like age and sex. For women, LH fluctuates throughout the menstrual cycle, with higher levels before ovulation. For men, normal LH levels are generally lower. Your doctor will interpret results in the context of your health and medical history.
Can lifestyle factors affect LH levels?
Yes. Stress, poor sleep, extreme weight changes, and certain medications (e.g., birth control, antidepressants) can influence LH levels. Maintaining a healthy lifestyle and discussing medications with your doctor can help ensure accurate test results.
  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