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Serum or plasma concentration of total homocysteine

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of homocysteine, a type of amino acid, in your blood. It helps assess risks related to heart disease and other health conditions.

Quick summary

["Homocysteine levels can indicate potential heart or blood vessel risks."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
13600-2
Short code
11DC 15M p 250 ug ACTH SerPl-mCnc
Synonyms
11DC 15M p 250 ug ACTH SerPl-mCnc
Category
hormone
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
60
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have a history of heart disease, stroke, or blood vessel problems, or if you have risk factors like high blood pressure, diabetes, or smoking. It may also be used to monitor treatment for conditions like pernicious anemia or kidney disease.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw blood. If you’re on blood thinners, let your provider know before the test.

What the Results Mean

High levels of homocysteine may increase your risk of blood clots, heart disease, or nerve damage. Low levels are generally not concerning unless related to specific medications or conditions.

Common Causes of Abnormal Results

Elevated homocysteine can be caused by genetic factors, vitamin deficiencies (like folate or B12), kidney disease, or certain medications. Low levels might be due to medications that lower homocysteine or rare genetic conditions.

Reference range

NCBI: ACTH 10-60 pg/mLN/A

Specimen: serum

Typically collected in the morning (8-10 AM). Inform your provider if taking steroid medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated homocysteine is an independent risk factor for cardiovascular disease and vascular complications. It can help guide treatment plans for conditions like homocystinuria or as a monitoring tool for patients on folate/B12 supplements.

Short name

Total Homocysteine

Frequently asked questions

Will I need to fast before this test?
No fasting is required for this test. However, if you’re taking folate or B vitamins, let your provider know as it may affect results.
What does a normal range mean for me?
A normal range doesn’t mean your levels are perfectly healthy—it’s a general guideline. Your actual results will be compared to your specific health needs and any medications you’re taking.
Can I take supplements to lower homocysteine?
Yes, folate, vitamin B6, and B12 supplements may help lower homocysteine levels. Always follow your provider’s advice before starting new supplements.
  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 17, 2026. · Read our editorial policy