LH (Luteinizing Hormone)
Measures luteinizing hormone levels to evaluate fertility, ovulation timing, and reproductive health.
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Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
Luteinizing hormone (LH) is produced by the pituitary gland and serves as a critical trigger in the reproductive system. In women, LH surges sharply at mid-cycle to initiate ovulation, causing the dominant follicle to release its egg. This LH surge is the physiological event that ovulation predictor kits detect. Outside of the surge, LH contributes to the regulation of the menstrual cycle and supports progesterone production by the corpus luteum after ovulation. In men, LH stimulates the Leydig cells in the testes to produce testosterone, which is essential for sperm production and the maintenance of male sexual characteristics.
During puberty, rising LH levels in both sexes drive the hormonal changes responsible for sexual maturation. LH measurement helps healthcare providers evaluate menstrual irregularities, investigate infertility, assess pituitary function, and determine whether ovulation is occurring. The test is also useful for diagnosing conditions like polycystic ovary syndrome (PCOS), where an elevated LH-to-FSH ratio is a common finding.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals experiencing fertility challenges or difficulty conceiving after trying for several months
- Those with irregular menstrual periods, absent periods, or unpredictable ovulation patterns
- Individuals seeking to identify their optimal fertile window for conception planning
- Those experiencing symptoms that may suggest hormonal imbalances affecting reproductive health
- Individuals going through perimenopause or menopause transition who want to monitor hormonal changes
- Those with concerns about early or delayed puberty in adolescents
What to expect
Preparation
No special preparation is typically required for this test. However, individuals who menstruate may be advised to have the test performed on a specific day of their menstrual cycle depending on the clinical question. Those taking biotin supplements should inform their healthcare provider, as high doses may interfere with test results.
Sample Type
A blood sample is collected through a standard blood draw from a vein in the arm
Collection
The blood collection process takes just a few minutes. A healthcare professional will clean the area, insert a thin needle into a vein, and collect the blood sample in a tube. Some individuals may experience mild discomfort during the needle insertion.
Turnaround
Results are typically available within 1-2 business days after the sample reaches the laboratory
Understanding your results
LH levels fluctuate substantially throughout the menstrual cycle and vary by age, sex, and reproductive status. For this reason, the timing of the blood draw relative to the menstrual cycle is essential context for interpretation. In women, a dramatic mid-cycle LH spike is normal and expected; the same level measured during the follicular or luteal phase would carry different significance. Reference ranges differ between laboratories, and healthcare providers interpret LH alongside FSH, estradiol, progesterone, symptoms, and clinical history to build a complete picture of reproductive function. In men, LH results are evaluated in combination with testosterone levels to assess whether the pituitary-gonadal axis is functioning appropriately.
| Population | Reference Range | Notes |
|---|---|---|
| Adult Females (Follicular/Luteal Phase) | 2.1-12.9 IU/L | Follicular phase 2.1-10.9 IU/L, luteal Phase: 1.2-12.9 IU/L |
| Adult Females (Mid-cycle Surge) | 19.2-103 IU/L | Mid-cycle 19.2-103 IU/L during ovulation surge |
| Adult Males | 1.2-8.6 IU/L | Adult Male (and children 14+ years): 1.2-8.6 IU/L |
| Postmenopausal Females | 14-52 IU/L | After menopause, normal LH levels range from around 14-52 IU/L |
Reference ranges shown are general guidelines. Your lab report will include the specific reference range used by the laboratory that processed your sample, which is the authoritative range for interpreting your results.
What does a “Low” result mean?
Low LH levels typically suggest issues with the pituitary gland or hypothalamus rather than the reproductive organs themselves. Low levels of LH may be a sign of "secondary ovarian failure," which means the problem starts with the pituitary gland or hypothalamus (a part of the brain). Low levels of LH mean the issue is with the pituitary gland or hypothalamus. A low LH level is commonly seen in people who have a problem with their pituitary gland: a common cause can be stress. Low LH level can also be caused by diet and lifestyle factors. In children, consistently low levels may indicate delayed puberty or other developmental concerns that warrant further evaluation.
What does a “High” result mean?
Elevated LH levels may indicate various conditions depending on the individual's age and sex. High levels of LH in a woman's blood can be a sign of what's called "primary ovarian failure," which means that the problem is with the ovaries themselves. Doctors often can't pinpoint why primary ovarian failure happens. As you age and go through menopause, your LH levels will increase as your levels of estrogen and progesterone decrease. In males, high levels of LH in the blood are a sign of a problem with the testicles and can be a sign of primary testicular failure. A high LH level is commonly seen in people with PCOS or can be caused by certain lifestyle factors. In children, elevated levels may suggest early onset of puberty.
Privacy & confidentiality
All test orders are authorized and results reviewed by an independent, board-certified physician who is not the patient's personal doctor. At LevelPanel, we understand that fertility and hormone testing can be deeply personal matters. Your LH test results are handled with the utmost confidentiality and privacy protection. Your results are <u>not reported to your doctor</u> unless you specifically choose to share them, and they are <u>not part of your medical records</u> maintained by healthcare institutions. The testing is also <u>not on insurance statements</u> or EOBs (Explanation of Benefits), ensuring complete privacy from insurance companies and employers. We use secure, encrypted systems to protect your personal health information and maintain strict confidentiality protocols. No doctor visit is required to order this test, allowing you to take control of your reproductive health privately and conveniently. Only you have access to your results through our secure online portal, giving you the peace of mind to explore your fertility status without external pressures or unwanted disclosure.
Frequently asked questions
Related tests
FSH (Follicle Stimulating Hormone)
Often tested together with LH to provide comprehensive reproductive hormone assessment
View TestTestosterone Test
LH directly stimulates testosterone production, making this combination useful for male fertility evaluation
View TestEstradiol Test
Works with LH in the menstrual cycle regulation and ovarian function assessment
View TestProgesterone Test
Helps confirm ovulation occurred after LH surge detection
View TestRelated conditions
Related articles
Last reviewed: April 2026
CPT Code: 83002
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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