What is the Homocysteine test?

The Homocysteine blood test measures the level of homocysteine, an amino acid produced during normal protein metabolism. Under healthy conditions, homocysteine is rapidly converted into other compounds using vitamin B12, vitamin B6 and folate.

When this process is impaired, homocysteine accumulates in the blood. Elevated levels are associated with increased cardiovascular risk, endothelial dysfunction, and potential neurological effects.

Homocysteine testing is commonly used in cardiovascular risk assessment, nutritional evaluation, and investigation of unexplained vascular or neurological symptoms.

Why do I need a Homocysteine test?

Raised homocysteine levels may indicate impaired methylation or vitamin deficiency and are linked to increased risk of cardiovascular and cerebrovascular disease.

You may need a Homocysteine test if you:

• Have a family history of heart disease or stroke
• Have unexplained cardiovascular risk
• Have vitamin B12, B6 or folate deficiency
• Experience cognitive or neurological symptoms
• Have a history of blood clots
• Have chronic fatigue
• Follow a restrictive or vegan diet
• Are being assessed for metabolic or methylation issues

Symptoms or conditions associated with high homocysteine may include:

• Cardiovascular disease
• Stroke or TIA
• Cognitive decline
• Peripheral vascular disease
• Pregnancy complications

Benefits of the Homocysteine test

• Assesses cardiovascular risk
  Elevated levels are linked to vascular disease.
• Identifies vitamin B deficiencies
  Sensitive marker for B12, B6 and folate status.
• Supports stroke risk evaluation
  Useful in cerebrovascular assessment.
• Relevant for neurological health
  Elevated levels may affect cognition and nerves.
• Guides nutritional intervention
  Supports targeted supplementation.
• Clinically recognised biomarker
  Used in cardiovascular and metabolic medicine.
• Useful in preventive health screening
  Identifies modifiable risk factors.
• Simple blood test
  Requires only a single sample.

Step by step – how the test works

You can access Homocysteine testing UK-wide through two options:

1. Clinic appointment
   Choose your nearest UK clinic, where a healthcare professional will take your blood sample.
2. At-home or hotel visit (£60 extra)
   A qualified phlebotomist comes to your home or hotel, so you don’t need to travel.

Your sample is analysed in an accredited UK laboratory, and results are delivered securely.

Your results explained

Low homocysteine levels

Generally not clinically concerning and usually reflect adequate vitamin status.

Typical UK reference range:

• < 5 µmol/L

Normal homocysteine levels

Suggest balanced methylation and adequate vitamin B status.

Typical UK reference range:

• 5–15 µmol/L

High homocysteine levels

Indicate increased cardiovascular risk or possible vitamin deficiency.

Typical UK reference range:

• > 15 µmol/L

Reference ranges may vary slightly between laboratories and clinical context.