5-OH-indoleacetic Acid

Optimal Result: 3.8 - 12.1 mmol/mol creatinine.

5-OH-indoleacetic Acid is a breakdown product of serotonin that is excreted in the urine. Serotonin is a hormone found at high levels in many body tissues. Serotonin and 5-OH-indoleacetic Acid are produced in excess amounts by carcinoid tumors, and levels of these substances may be measured in the urine to test for carcinoid tumors.

5-OH-indoleacetic Acid is found to be associated with:

- Aromatic l-amino acid decarboxylase deficiency an inherited disorder that affects the way signals are passed between certain cells in the nervous system.)

- Celiac disease (an autoimmune disorder where the ingestion of gluten leads to damage in the small intestine)

- Sepiapterin reductase deficiency (a condition characterized by movement problems)

Women generally have lower levels than men.

Numerous drugs affect the excretion of 5-OH-indoleacetic Acid by different mechanisms, including increased serotonin synthesis, metabolism, and release and inhibition of uptake. The following medications can interfere with 5-OH-indoleacetic Acid results. Proper preparation before the test is essential. Medication and dietary restrictions are required to prevent false-positive results. If clinically feasible, discontinue the following medications at least 48 hours before specimen collection. 

- Acetaminophen (Tylenol or generic versions)

- Aspirin

- Antihistamines

- Cough syrups

- Cold and flu medications

One should also avoid caffeinated beverages such as tea and coffee or caffeinated foods for 48 hours before and during specimen collection.

Certain medicines can raise or lower your 5-OH-indoleacetic Acid levels. These include:

- Aspirin

- Acetaminophen

- Ethyl alcohol

- Some antidepressants

- Cough medicines or antihistamines

- Medicines to relax muscles

References:

- Urinary sampling for 5HIAA and metanephrines determination: revisiting the recommendations, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527357/

- Guidelines for the diagnosis and management of carcinoid tumours. Part 1: the gastrointestinal tract. A statement from a Canadian National Carcinoid Expert Group. (https://www.ncbi.nlm.nih.gov/pubmed/17576444)

- A single fasting plasma 5-HIAA value correlates with 24-hour urinary 5-HIAA values and other biomarkers in midgut neuroendocrine tumors (NETs). (https://www.ncbi.nlm.nih.gov/pubmed/23160483)

- Aromatic l-amino acid decarboxylase deficiency, https://ghr.nlm.nih.gov/condition/aromatic-l-amino-acid-decarboxylase-deficiency

- WHAT IS CELIAC DISEASE?, https://celiac.org/celiac-disease/understanding-celiac-disease-2/what-is-celiac-disease/

- Sepiapterin reductase deficiency, https://ghr.nlm.nih.gov/condition/sepiapterin-reductase-deficiency

What does it mean if your 5-OH-indoleacetic Acid result is too low?

Low 5-OH-indoleacetic Acid indicates inadequate production of serotonin. Symptoms include: constipation, depression, fatigue, insomnia, attention deficit and behavioral disorders.

Lower levels of 5-OH-indoleacetic Acid may mean you have:

- Depression

- Migraines

- What might affect the test results?

Foods and medications associated with decreased urinary HIAA results:

- Aspirin

- chlorpromazine (Thorazine)

- corticotropin

- dihydroxyphenylacetic acid

- alcohol

- gentisic acid

- homogentisic acid

- hydrazine derivatives

- imipramine (Tofranil®)

- isocarboxazid (Marplan)

- keto acids

- levodopa

- MAO inhibitors

- methenamine

- methyldopa (Aldomet®)

- perchlorperazine

- phenothiazines (Compazine®)

- promazine

- promethazine (Mepergan®)

What does it mean if your 5-OH-indoleacetic Acid result is too high?

High 5-OH-indoleacetic Acid can be caused by SSRI medication, 5-HTP supplementation, increased release of serotonin from the central nervous system, digestive system or platelets. Very high 5-OH-indoleacetic Acid levels can ironically indicated a tryptophan deficiency, as this may cause an increased conversion of tryptophan to serotonin.

Higher levels of 5-OH-indoleacetic Acid may mean you have:

- Carcinoid tumors

- Noncarcinoid tumors

- Cystic fibrosis

- Malabsorption

Increased urine 5-OH-indoleacetic Acid concentration is common and may be the result of improper specimen collection, consumption of serotonin containing foods or dietary supplements, drug interference, or malabsorption syndromes. Significant elevation (ten times the upper reference limit) of urine 5-OH-indoleacetic Acid may indicate the presence of a carcinoid tumor.

Eating certain foods containing serotonin can raise 5-OH-indoleacetic Acid. These foods include:

- Cheese

- Bananas

- Pineapple

- Kiwi

- Plums

- Tomatoes

- Eggplant

- Avocados

- Certain nuts, including walnuts and pecans

Strenuous exercise can also raise your 5-OH-indoleacetic Acid levels.

Foods and medications associated with increased urinary 5-OH-indoleacetic Acid results:

- Acetaminophen

- acetanilide

- caffeine

- coumaric acid

- diazepam (Valium®)

- ephedrine

- fluorouracil

- glycerol guaiacolate (Guaifenesin)

- melphalan (Alkeran®)

- mephenesin

- methamphetamine (Desoxyn)

- methocarbamol (Robaxin®)

- naproxen

- nicotine

- phenacetin

- phenmetrazine

- phenobarbital

- phentolamine

- rauwolfia

- reserpine

10 000+ happy customers
100% satisfaction
★ ★ ★ ★ ★ customer support

Understand blood, stool, and urine medical results from all your laboratories.

Upload Your Personal Results

Upload Personal Results

For professional account plans go here

for professional account plans go here

Monthly plan

Annual plan

Own it for life

  • Subscription
  • Data entry service included

    Data entry service

    Our exclusive data entry service is a convenient way to get your results into your private dashboard. Simply attach an image or a file of your lab test results, and one of our qualified data entry team members will add the results for you. We support all sorts of files, whether PDFs, JPGs, or Excel. This service is excellent whether you have a lot of reports to upload or are too busy to do the data entry yourself.

  • Instant interpretation
  • Use free data entry form

    Free data entry form

    We strive to make the data entry process easy for you. Whether by offering dozens of templates to choose from that pre-populate the most popular laboratory panels or by giving you instant feedback on the entered values. Our data entry forms are an easy, fast, and convenient way to enter the reports yourself. There is no limit on how many lab reports you can upload.

  • 4000+ biomarkers explained
  • Nutrition recommendations
  • Cancel anytime

Complete

$15 /month

billed every month

  • monthly
  • $15 per report
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ Free data entry form
  • ✓ Unlimited data
  • ✓ $15 data entry service
  • ✓ Cancel anytime

Most popular

Data entry included

Advanced

$79 /year

$6.60/month billed annually

  • yearly
  • 5 reports free
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ We enter 5 reports for you
  • ✓ Yearly subscription
  • ✓ Cancel anytime

Data entry included

Unlimited

$250 /once

own it for life

  • pay once
  • 10 reports free
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ We enter 10 reports for you
  • ✓ No subscription
  • ✓ Dedicated support
  • ✓ Unlimited access

Are You a Health Professional?

Get started with our professional plan

Welcome to Healthmatters Pro.

Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more

Pro Monthly Plus

for health professionals

  • ✓ Track multiple clients results
  • ✓ No setup fees
  • ✓ No hidden costs
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Includes data entry service
  • ✓ Personal training and support
  • ✓ Cancel anytime

$75 per month

Use promo code to save 10% off any plan.


We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.