Serotonin, 24-Hour Urine
About Serotonin, 24-Hour Urine
| Field | Value |
|---|---|
| Also Known As | Serotonin urine test, 5-HT 24-hour urine, Urinary serotonin |
| Sample Type | 24-hour urine collection (sterile container) |
| Fasting Required | No fasting required; dietary restrictions apply for 48 hours before and during collection |
| Report Time | 1 Day |
| Recommended For | Adults of all genders, primarily when carcinoid tumours are suspected |
| Price | Starting at ₹5000 |
What Is a Serotonin 24-Hour Urine?
The Serotonin 24-hour urine test checks how much serotonin is released in urine over a day. Serotonin is a chemical made in the brain, lungs, and gut that affects mood, sleep, and digestion.
This test, also known as the urinary serotonin test, is typically performed when a doctor suspects the presence of a carcinoid tumour or carcinoid syndrome. It involves collecting urine for 24 hours and analysing it using a method called spectrophotometry.
What Does a Serotonin, 24 Hours Urine Measure?
This test evaluates the total serotonin excreted in urine over a full day. The longer collection period provides a clearer understanding of serotonin production compared to a single sample.
| Parameter | What It Reflects |
|---|---|
| Serotonin, 24-Hour Urine | Total serotonin excreted over 24-hour, reflecting overall serotonin production in the body |
Serotonin is made primarily by nerve cells and specialised cells in the gut and lungs. It helps transmit nerve signals, regulate blood vessel tone, and influence the sleep-wake cycle.
Why Is a Serotonin, 24 Hours Urine Done?
Doctors order this test when certain symptoms or clinical findings suggest that serotonin-producing tumours may be present.
Common Symptoms That May Require This Test
The following symptoms are the most frequent reasons a doctor may request a serotonin 24-hour urine test:
- Skin flushing (the face and upper chest turn red and feel warm)
- Frequent watery diarrhoea with abdominal cramps
- Wheezing or shortness of breath
- Rapid heartbeat
- Unexplained weight loss
Conditions This Test Can Help Detect
This test helps identify conditions linked to excess serotonin production. These include:
- Carcinoid tumours (slow-growing neuroendocrine tumours in the gut or lungs) causing carcinoid syndrome
- Foregut carcinoid tumours that produce a serotonin precursor called 5-HTP, which the kidneys convert into serotonin
- Metastatic neuroendocrine tumours that have spread from the midgut to the liver
Serotonin, 24-Hour Urine for Chronic Disease Monitoring
In patients whose tumours mainly secrete 5-HTP, urinary serotonin is the preferred marker for tracking disease progression.
For other patients, it is used alongside urinary 5-HIAA and serum chromogranin A measurements.
The test may be repeated periodically to assess how well treatment is working in carcinoid tumour patients.
How to Prepare and What to Expect
The serotonin test procedure requires careful preparation for accurate results. Following the instructions below closely is important.
Do You Need to Fast?
No fasting is required for this test. However, strict dietary restrictions must be followed for 48 hours before collection begins and throughout the entire 24-hour collection period.
If your doctor has ordered additional tests at the same time, ask whether fasting may be required for those.
Practical Tips Before Your Test
Keep these points in mind before and during your 24-hour serotonin urine test:
- Bring a detailed clinical history including your symptoms, previous test results, and relevant medical records, as this is required for the test
- Avoid foods high in serotonin or tryptophan for 48 hours before and during collection: these include bananas, avocados, pineapple, kiwifruit, tomatoes, plums, eggplant, dates, walnuts, pecans, grapefruit, cantaloupe, and plantains
- Tell your doctor about all medications you take, especially lithium, MAO inhibitors, methyldopa, morphine, reserpine, and SSRIs such as fluoxetine; these should be stopped at least 72 hours before collection, but only after consulting your doctor
- Avoid heavy smoking or nicotine use during the collection period, as cotinine (a nicotine breakdown product) can falsely raise serotonin readings
- Keep the collection container refrigerated throughout the 24-hour period
Step-by-Step Procedure
Here is how the 24-hour urine collection works:
- On the morning of day one, urinate into the toilet as usual when you wake up. Do not collect this first sample.
- From that point onwards, collect every urine sample in the sterile container provided for the next 24 hours.
- On the morning of day two, collect your first morning urine into the container. This is your last collection.
- Cap the container securely and label it with your name, the date, and the time you finished.
- Keep the container refrigerated (2 to 8°C) throughout the collection.
- Return the labelled container to the Lupin Diagnostics centre or hand it to the home collection professional as instructed.
Factors That Can Affect Accuracy
Several factors can alter results and lead to incorrect readings:
- Collecting urine for more or less than 24 hours, or missing some collections
- Eating serotonin-rich or tryptophan-rich foods before or during collection
- Certain medications or supplements (particularly SSRIs, MAO inhibitors, and lithium)
- Heavy nicotine or smoking exposure during collection
- Strenuous exercise or extreme stress
- Dehydration
Understanding Your Serotonin 24-Hour Urine Results
Results must always be reviewed alongside your clinical history and other relevant investigations. Below is the reference range for this test.
| Parameter | Normal Range | Unit |
|---|---|---|
| Serotonin, 24-Hour Urine | 210 or below | mcg/24 hours |
Reference values apply to adults of all ages. Source: Mayo Clinic Laboratories.
These ranges are general guidelines. Your doctor will interpret your results based on your age, health history, and other factors. Always consult a qualified healthcare professional for personalised medical advice.
Results During Special Conditions
Certain situations can affect the reliability of your result. These are worth discussing with your doctor.
Eating serotonin-rich or tryptophan-rich foods such as bananas, avocados, pineapple, or walnuts within 48 hours of collection can raise urinary serotonin levels significantly, producing a false-high result.
Medications have a stronger effect on urine serotonin than on blood serotonin. Some drugs, especially fluoxetine, have long half-lives and may require several months after stopping before serotonin levels return to baseline. Conversely, SSRIs can deplete platelet serotonin and cause a false-low result.
How to Maintain Healthy Levels
These general tips support accurate readings and overall wellbeing:
- Follow all dietary restrictions strictly before and during collection to avoid misleading results
- Share a full list of your medicines and supplements with your doctor before the test
- Refrain from smoking or heavy nicotine use throughout the collection day
Lupin Diagnostics Serotonin, 24-Hour Urine Price and Home Collection
The Serotonin test price at Lupin Diagnostics starts at ₹2,500, and home sample collection is available. The following table shows approximate city-wise pricing.
| City | Approximate Price (₹) |
|---|---|
| BHOPAL | 5000 |
| CHENNAI | 5000 |
| HYDERABAD | 5000 |
| KOLKATA | 5000 |
| NAVI MUMBAI | 5000 |
| PUNE | 5000 |
Prices are indicative and may vary by location. Please confirm the current price at the time of booking.
How to Book
Booking your Serotonin test online is straightforward:
- Select the test on the Lupin Diagnostics website.
- Choose your city and preferred time slot.
- Opt for home sample collection by a certified phlebotomist, or visit your nearest Lupin Diagnostics centre.
- Receive your report via email or WhatsApp within the stipulated turnaround time.
Home Collection
Serotonin test home collection is available across cities. A trained phlebotomist will visit your home, provide the sterile collection container, and give you clear instructions for the 24-hour procedure. All samples are processed in NABL-accredited laboratories. Your digital report will be accessible via email or WhatsApp once ready.
Frequently Asked Questions
This test is primarily used to help diagnose carcinoid tumours and carcinoid syndrome by measuring how much serotonin is produced over a full day. It is usually ordered alongside other markers such as urinary 5-HIAA and serum chromogranin A to build a complete picture.
Serotonin levels in urine vary throughout the day. Collecting all urine over 24 hours averages out these fluctuations, making it much easier to detect a genuine elevation. A single sample could give a misleadingly normal or high reading.
For 48 hours before and during the collection period, avoid bananas, avocados, pineapple, kiwifruit, tomatoes, plums, eggplant, dates, walnuts, and other nuts. These foods are rich in serotonin or tryptophan and can falsely raise your result.
Yes. Lithium, MAO inhibitors, methyldopa, morphine, and reserpine can raise serotonin levels, while SSRIs such as fluoxetine can lower them. Inform your doctor about all medicines you take. Do not stop any medication without your doctor's approval.
Keep the collection container in the refrigerator (between 2 and 8°C) throughout the entire 24-hour period. This preserves the sample and helps ensure accurate results.
The key symptoms of carcinoid syndrome are skin flushing, frequent watery diarrhoea, wheezing, and a rapid heartbeat. Some patients develop carcinoid heart disease over time. If you have these symptoms, speak to your doctor about appropriate investigations.
No. This is a urine-based test, so there is no blood draw or injection involved. The main requirement is careful collection and refrigeration of all urine over 24 hours, along with following the dietary and medication guidelines given by your doctor.
Serotonin, 24-Hour Urine
