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Melatonin in Cerebrospinal Fluid (CSF)

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

This test measures the amount of melatonin, a hormone produced by the pineal gland, in your cerebrospinal fluid. Melatonin helps regulate sleep-wake cycles.

Quick summary

["Assessing melatonin levels in CSF may help diagnose sleep disorders or other neurological conditions."]

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

Key facts at a glance

LOINC
49725-5
Short code
Melatonin CSF-mCnc
Synonyms
Melatonin CSF-mCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms like insomnia, irregular sleep patterns, or suspected pineal gland issues. It could also be part of evaluating conditions affecting brain chemistry or sleep regulation.

What to Expect Before the Test

No special preparation is typically needed. You may receive a local anesthetic for comfort during the lumbar puncture procedure. Avoid caffeine or bright lights before the test, as they can influence melatonin levels.

How the Test Works

A small amount of cerebrospinal fluid is collected through a needle inserted into your lower back. The fluid is then sent to the lab for analysis to measure melatonin concentration.

What the Results Mean

Results are compared to a reference range specific to melatonin in CSF, though exact values may vary by lab. Abnormal results may indicate hormonal imbalances, neurological disorders, or other conditions affecting melatonin production or sleep regulation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Melatonin CSF

Frequently asked questions

What Are Common Causes of Abnormal Results?
Abnormally high melatonin levels in CSF might suggest conditions like pineal gland tumors or certain sleep disorders. Low levels could be linked to genetic factors, certain medications, or disorders affecting melatonin synthesis.
How Might Results Affect My Treatment?
If your results are abnormal, your doctor may recommend further testing, adjustments to medications (e.g., melatonin supplements), or lifestyle changes to support healthy sleep patterns. Follow-up may include additional sleep studies or consultations with specialists.
Will I Need to Do Anything After the Test?
You may experience mild soreness or bruising at the injection site. Rest and stay hydrated, but avoid strenuous activity for a few hours. Contact your provider if you have severe pain, fever, or signs of infection.
  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