Melatonin
A blood test that measures melatonin levels to assess sleep-wake cycles and circadian rhythm function.
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What this test measures
Melatonin is a hormone produced by the pineal gland that plays a crucial role in regulating sleep-wake cycles and circadian rhythms. The pineal gland releases melatonin in response to darkness, conveying the message of nighttime to the body's internal clock and inducing sleep-related physiological functions. Endogenous melatonin concentrations typically range from less than 0.02 to 0.2 ng/mL and vary significantly based on the time of day and individual age.
Melatonin levels naturally peak during nighttime hours (around 3 AM) and drop to much lower levels during daylight hours. In healthy individuals, melatonin secretion follows a robust circadian rhythm with maximum levels occurring around 3 to 4 AM, and the daily rise of melatonin correlates with increased sleep propensity about 2 hours before regular bedtime. This test measures the concentration of melatonin in blood to help evaluate whether the body's natural sleep-wake cycle is functioning properly.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals experiencing chronic insomnia or difficulty falling asleep despite good sleep hygiene practices may benefit from this test.
- Those with suspected circadian rhythm sleep disorders, such as delayed sleep phase syndrome or shift work sleep disorder, should consider melatonin testing.
- People who frequently travel across time zones and struggle with persistent jet lag symptoms may find this test helpful.
- Individuals with autism spectrum disorder, ADHD, or other neurodevelopmental conditions often associated with sleep disturbances should consider testing.
- Those with seasonal affective disorder (SAD) or symptoms that worsen during darker months may benefit from evaluating their melatonin levels.
What to expect
Preparation
No special preparation is required for this test. However, timing of the blood draw is important as melatonin levels vary dramatically throughout the day. Your healthcare provider will advise on the optimal collection time based on your specific symptoms.
Sample Type
A standard blood draw is performed, typically from a vein in the arm. The procedure takes just a few minutes and requires only a small amount of blood.
Collection
During your visit to the lab, a trained phlebotomist will clean the collection site and use a sterile needle to draw blood into a specialized tube. The sample is then labeled and prepared for laboratory analysis.
Turnaround
Results are typically available within 3 to 5 business days after the sample reaches the laboratory. You will receive your results securely through your patient portal.
Understanding your results
Normal melatonin levels typically range between 0.02-0.2 ng/mL, though reference ranges may vary by laboratory. Results must be interpreted in the context of collection time, as levels are naturally much higher at night (18-197 pg/mL) compared to morning hours (3-80 pg/mL).
| Population | Reference Range | Notes |
|---|---|---|
| Adults (daytime collection) | 0.02-0.2 ng/mL | May vary significantly based on time of collection and age |
| Adults (nighttime peak) | 18-197 pg/mL | Peak levels typically occur around 3-4 AM |
Reference ranges may vary by laboratory and individual factors. Results should be interpreted by a healthcare provider in the context of your overall health.
What does a “Low” result mean?
Low melatonin levels may be associated with high stress, particularly elevated cortisol at night, which can suppress the pineal gland and reduce melatonin production. Reduced melatonin secretion has been observed in certain psychiatric conditions, including schizophrenia and neurocognitive disorders, often due to a smaller pineal gland volume and increased calcification. Dysfunction in melatonin production has been associated with various conditions affecting the nervous system, including Alzheimer's disease, Parkinson's disease, depression, and cardiovascular disorders. Low melatonin is particularly common in pediatric populations with neurodevelopmental disorders, including autism spectrum disorder and neurogenetic disorders, which may explain abnormal sleep-wake cycle development. Multiple disorders associated with intellectual dysfunction have been associated with decreased melatonin production, and supplementation may help improve sleep and stabilize circadian rhythms.
What does a “High” result mean?
Elevated melatonin levels may be associated with sleep disturbances, difficulty waking in the morning, and feelings of lethargy during the day. Higher melatonin production is often noted during darker months of autumn and winter and may contribute to seasonal affective disorder. High levels may also be linked to inhibition of ovulation in women, decreased body temperature, and have been noted during the manic phase of bipolar mood disorder. Certain medications can affect melatonin levels. Many antidepressant drugs may stimulate melatonin production, including fluvoxamine, desipramine, and most MAO inhibitors, while Prozac may lower melatonin levels. If melatonin is inappropriately elevated during daytime hours, it may suggest a disrupted circadian rhythm that could benefit from light therapy or other interventions.
Privacy & confidentiality
All melatonin test results are kept strictly confidential and protected under HIPAA regulations. Your results will not be shared with insurance companies or added to your medical records without your explicit consent. No doctor visit is required to order this test, giving you complete control over your health information.
Frequently asked questions
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CPT Code: 80375
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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