Serotonin (Blood)
Private Serotonin blood testing in London for £180.99, measuring one circulating serotonin marker with results expected in around 10 days.
Turnaround time
10 business days
Biomarkers count
1
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Overview of the Serotonin (Blood) Test
The Serotonin (Blood) test measures circulating serotonin in blood, providing specialist biochemical information where abnormal serotonin production is being investigated.
The test assesses 1 specialist biomarker: Serotonin.
Serotonin, also known as 5-hydroxytryptamine or 5-HT, is an important signalling molecule produced from the amino acid tryptophan.
Although serotonin is widely associated with brain neurotransmission, most of the body's serotonin is produced within the gastrointestinal system.
Platelets also take up and store circulating serotonin.
This distinction is important because a blood serotonin test does not directly measure serotonin activity within the brain.
It should therefore not be presented as a blood test for mood, happiness, depression or anxiety.
One established clinical reason to measure peripheral serotonin is the investigation of selected neuroendocrine tumours, particularly serotonin-secreting carcinoid tumours.
Some neuroendocrine tumours can release large amounts of serotonin.
The hormone is metabolised to 5-hydroxyindoleacetic acid, or 5-HIAA, which can be measured in urine or blood depending on the laboratory pathway.
For this reason, 5-HIAA is often an important complementary marker when carcinoid syndrome is being considered.
Symptoms associated with serotonin-secreting neuroendocrine tumours can include flushing, diarrhoea, wheezing and, in established disease, cardiac complications.
However, these symptoms are non-specific.
A raised serotonin concentration does not diagnose a neuroendocrine tumour by itself.
Diet, medication, specimen handling and laboratory methodology can influence the result.
This test also has special specimen requirements.
Current specialist laboratory guidance requires dedicated collection tubes and frozen whole-blood processing.
The test should therefore be arranged through a collection pathway able to meet those requirements.
What Does the Serotonin (Blood) Test Check?
The test measures circulating Serotonin and can provide specialist biochemical information where excessive peripheral serotonin production is being investigated. This test measures 1 specialist biomarker.
Serotonin
Measures circulating serotonin in blood, supporting specialist assessment of abnormal peripheral serotonin production, particularly where a serotonin-secreting neuroendocrine tumour is being considered.
Who May Benefit From the Serotonin (Blood) Test?
Blood Serotonin testing is a specialist investigation rather than a routine mental-health or wellness test.
People undergoing investigation for a serotonin-secreting neuroendocrine tumour - Serotonin can provide supplementary biochemical information in the appropriate clinical setting.
People with symptoms suggestive of carcinoid syndrome under specialist assessment - Laboratory testing can include Serotonin and 5-HIAA.
People with a previous raised Serotonin result - Repeat testing may help establish whether the elevation persists.
People with an abnormal 5-HIAA result - Blood Serotonin can provide complementary biochemical information in selected cases.
People with known neuroendocrine tumours under specialist care - Serial biochemical markers may occasionally form part of monitoring.
People with unexplained flushing and diarrhoea after more common causes have been assessed - Neuroendocrine testing may be considered where the clinical pattern is appropriate.
People specifically advised to have Serotonin measured by an endocrinologist or oncologist - Interpretation is most useful when the clinical question is clearly defined.
How to Prepare
Do not stop antidepressants or other prescribed medicines simply to change the laboratory result.
This test requires specialist specimen handling, including dedicated collection materials and freezing, so collection must be arranged appropriately.
Symptoms and Reasons to Consider the Serotonin (Blood) Test
Abnormal peripheral serotonin production can be associated with carcinoid syndrome, although the symptoms are not specific.
Recurrent unexplained facial or upper-body flushing - Serotonin-secreting neuroendocrine tumours are one uncommon cause.
Persistent unexplained diarrhoea - Carcinoid syndrome can cause secretory diarrhoea.
Wheezing with flushing or diarrhoea - Bronchospasm can occur in established carcinoid syndrome.
A known neuroendocrine tumour - Serotonin-related markers can sometimes contribute to biochemical monitoring.
A previous elevated 5-HIAA result - Additional serotonin assessment may provide supplementary information.
A previous raised blood Serotonin result - Repeat measurement can establish the trend.
A blood Serotonin test does not measure serotonin levels in the brain and should not be used to diagnose depression, anxiety or another psychiatric condition.
Flushing and diarrhoea have many common causes, and neuroendocrine tumours are relatively uncommon.
The result should therefore be interpreted in a specialist clinical context.
How to Book Your Serotonin (Blood) Test
The Serotonin (Blood) test can be booked privately for specialist measurement of circulating serotonin.
Choose the Serotonin (Blood)
Select the individual blood Serotonin test online.
Select your sample collection option
Arrange an in-clinic blood draw or suitable professional phlebotomy pathway capable of meeting the specialist sample-handling requirements.
Attend your appointment
A trained healthcare professional collects the required blood specimen using the laboratory-specified collection materials.
Laboratory analysis
Your specimen undergoes specialist measurement of Serotonin.
Receive your results securely
Your authorised result is delivered securely and can be interpreted alongside 5-HIAA and other neuroendocrine investigations where appropriate.
When Will I Receive My Results?
The current specialist laboratory turnaround for Serotonin is approximately 10 days after laboratory receipt.
This assay requires specialist sample tubes or containers and frozen whole-blood handling.
The specimen undergoes dedicated biochemical analysis, quality-control procedures and result authorisation.
Turnaround begins when a suitable specimen reaches the specialist laboratory pathway.
Understanding Your Results
A raised Serotonin result indicates increased circulating serotonin according to the laboratory assay.
One possible cause is excessive serotonin production by a neuroendocrine tumour.
However, the result is not diagnostic by itself.
Diet, medication, specimen handling and other physiological factors can influence serotonin measurement.
A result should therefore be interpreted alongside symptoms and complementary investigations.
5-HIAA is particularly important because it is the principal metabolite of serotonin and can provide additional information where carcinoid syndrome is suspected.
A result within the laboratory range makes marked circulating serotonin excess less likely but does not independently exclude a neuroendocrine tumour.
Some neuroendocrine tumours do not produce serotonin.
Imaging, pathology and other biochemical markers can therefore remain necessary where clinical suspicion exists.
Why Book With London Blood Tests?
London Blood Tests provides private access to specialist circulating Serotonin measurement.
Measures circulating Serotonin directly - The test assesses the exact Serotonin biomarker listed by the laboratory.
Relevant to neuroendocrine investigation - Serotonin can be elevated in selected serotonin-secreting tumours.
Can complement 5-HIAA - Measuring the metabolite can provide additional biochemical information.
Suitable for repeat specialist monitoring - Previous abnormal results can be followed where clinically appropriate.
Correct specialist handling - Collection requirements include dedicated materials and frozen whole-blood processing.
Specialist laboratory analysis - Samples undergo dedicated biochemical testing.
Professional blood collection - Appropriate sample collection can be arranged.
Clear pricing - The Serotonin (Blood) test costs £180.99.
Private Serotonin (Blood) Blood Test in London
London Blood Tests provides private Serotonin blood testing for people requiring specialist assessment of circulating serotonin.
The test costs £180.99 and measures 1 specialist biomarker: Serotonin.
Results are expected approximately 10 days after laboratory receipt.
This is a specialist peripheral serotonin test and is not a measurement of serotonin activity within the brain.