Endogenous Serotonin (Mass Concentration) in Serum
This test measures the amount of serotonin, a chemical messenger in your body, found in your blood serum. Serotonin plays a role in mood regulation, digestion, and other bodily functions.
["Understanding your serotonin levels may help assess mood, digestive health, or other conditions."]
Key facts at a glance
- LOINC
- 104261-3
- Short code
- EDN Ser IA-mCnc
- Synonyms
- EDN Ser IA-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 17
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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 Might This Test Be Done?
Your healthcare provider may order this test if you have symptoms like depression, anxiety, digestive issues, or if they suspect an imbalance in serotonin levels. It could also be part of a broader evaluation for conditions like serotonin syndrome or certain neurological disorders.
What to Expect Before the Test
No special preparation is typically needed. You may be asked to fast for a few hours before the blood draw, but this depends on your healthcare provider’s instructions. Avoid consuming foods or supplements that might affect serotonin levels (like certain supplements or medications) for 24 hours before testing.
What Happens During the Test?
A healthcare professional will draw blood from a vein in your arm. The blood sample will be sent to a lab for analysis. The test involves measuring serotonin’s concentration in your serum.
What Are the Possible Results?
Results will be reported as a mass concentration value, which indicates how much serotonin is present in your blood. While reference ranges can vary by lab, your results will be compared to what is typical for healthy individuals of your age and gender.
Reference range
NCBI: NSE 0-17 ng/mLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Serotonin levels can be important in diagnosing or monitoring conditions related to mood disorders, gastrointestinal health, or neurological functions. Low or high serotonin levels may suggest conditions like depression, serotonin syndrome, or digestive disorders such as irritable bowel syndrome (IBS). Your healthcare provider will interpret the results in the context of your symptoms and medical history.
Short name
Serotonin Level
Frequently asked questions
What does a serotonin test measure?
How is serotonin tested?
Can diet or medications affect serotonin test results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy