Skip to content

Lysine in Serum (Mass Concentration)

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

This test measures the amount of lysine, an essential amino acid, present in your blood serum. Lysine is important for protein synthesis, immune function, and calcium absorption.

Quick summary

["Lysine levels can help assess protein metabolism and potential deficiencies."]

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

Key facts at a glance

LOINC
47691-1
Short code
Lysine SFr CSF
Synonyms
Lysine SFr CSF
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may order this test if you have symptoms or conditions linked to amino acid imbalances, such as muscle weakness, infections, or unusual fatigue. It could also be part of a broader evaluation for metabolic disorders or nutritional deficiencies.

What to Expect Before the Test

No special preparation is typically needed. You may have a small needle inserted into a vein in your arm to draw blood. If you’re on certain medications or have dietary restrictions, let your provider know beforehand.

What the Results Mean

Lysine levels are usually measured in milligrams per deciliter (mg/dL). While reference ranges vary by lab, very low levels may suggest protein malnutrition or certain metabolic disorders, while very high levels could indicate liver disease or overproduction of amino acids.

Common Conditions Linked to Lysine Levels

Low lysine levels might be associated with conditions like kwashiorkor (a severe protein deficiency), certain genetic metabolic disorders, or prolonged fasting. High levels could be linked to liver dysfunction or excessive protein breakdown.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Serum Lysine Level

Frequently asked questions

What causes abnormal lysine levels?
Abnormal lysine levels can result from dietary deficiencies (e.g., low-protein diets), certain genetic disorders affecting amino acid metabolism, liver disease, or conditions that disrupt protein synthesis or breakdown. Always discuss results with your healthcare provider.
How often should I get this test?
The frequency depends on your health status and symptoms. Your provider may recommend this test periodically if you have ongoing conditions like malnutrition, liver disease, or metabolic disorders. Regular monitoring is not standard for healthy individuals.
Can lifestyle changes affect lysine levels?
Yes, diet plays a key role. Consuming adequate protein (including lysine-rich foods like meat, fish, eggs, and legumes) can help maintain normal levels. Avoiding excessive alcohol or certain medications (e.g., some diuretics) may also support stable lysine levels.
  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