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Tyrosine concentration in serum/plasma

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

This test measures the amount of tyrosine, an amino acid important for making proteins and certain hormones in your body. It may be checked if you have conditions affecting protein metabolism or hormone production.

Quick summary

["Tyrosine levels help assess how well your body processes amino acids and certain hormones."]

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

Key facts at a glance

LOINC
47794-3
Short code
Tyrosine SFr Amn
Synonyms
Tyrosine SFr Amn
Category
chemistry
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may order this test if you have symptoms like fatigue, weight changes, or skin issues that could relate to amino acid or hormone imbalances. It might also be part of a broader evaluation for metabolic disorders or genetic conditions.

What to Expect Before the Test

No special preparation is usually needed. You may need to fast for a few hours before the blood draw, but always follow your provider’s instructions. Avoid smoking or consuming alcohol for a specified time before testing.

How the Test Works

A small sample of your blood is taken from a vein, typically in your arm. The sample is then analyzed in a lab to measure tyrosine levels using an immunoassay method, which detects the presence of tyrosine in your blood plasma or serum.

What the Results Mean

Results are compared to a reference range specific to your lab. While reference ranges can vary, abnormal levels may suggest conditions like phenylketonuria (a rare genetic disorder) or other metabolic issues. Your provider will discuss these results with you.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Tyrosine Level

Frequently asked questions

What does a high tyrosine level mean?
High tyrosine levels may indicate an overproduction of tyrosine or a metabolic disorder. This could be linked to conditions affecting amino acid metabolism or certain genetic disorders. Your provider will evaluate this in the context of your overall health and symptoms.
What does a low tyrosine level mean?
Low tyrosine levels might suggest an underlying issue with protein metabolism or hormone production. This could be part of a broader metabolic disorder or a condition affecting amino acid synthesis. Further testing and evaluation by your healthcare provider are needed to determine the cause.
Is fasting required for this test?
Yes, fasting may be required for a few hours before the test to ensure accurate results, especially if it’s part of a metabolic evaluation. Always follow your healthcare provider’s instructions to avoid any potential interference with the test.
  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