Helvy
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Metabolic
In the UK, the standard clinical (NHS) reference range for Homocysteine is <15 µmol/L, with <8 µmol/L considered the performance-optimised range. A result within these ranges suggests typical status; only a qualified clinician can interpret an individual reading.
Homocysteine is an amino acid produced as a byproduct of methionine metabolism. It is not obtained from diet but is generated internally and must be recycled back to methionine (via B12 and folate) or converted to cysteine (via B6). When this recycling pathway is impaired — by nutrient deficiency or genetic variants like MTHFR — homocysteine accumulates in the blood.
Optimal range · UK
<8 µmol/L
Performance-optimised band · clinical (NHS) range <15 µmol/L
Clinical (NHS)
<15 µmol/L
Performance
<8 µmol/L
Reference ranges for Homocysteine, not a personal result. Any individual reading should be interpreted by a qualified clinician.
Optimal ranges
| Range | Value |
|---|---|
| Clinical (NHS) reference range | <15 µmol/L |
| Performance-optimised range | <8 µmol/L |
The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best. A result in either range suggests typical status and is not a diagnosis; any individual reading should be interpreted by a qualified clinician.
Why it matters
Elevated homocysteine is an independent risk factor for cardiovascular disease, stroke, blood clots, and cognitive decline. It damages the endothelium (arterial lining), promotes oxidative stress, and impairs nitric oxide production — reducing blood flow and exercise performance. Critically, homocysteine is a functional marker of B12, folate, and B6 status — elevated levels often indicate deficiency in one or more of these vitamins even when serum levels appear 'normal'. It's particularly important for men with the MTHFR C677T variant (~40% of the population), who have impaired folate metabolism and tend to run higher homocysteine.
Symptoms
Low / Deficiency
High / Excess
Dietary sources
Supplementation
The homocysteine-lowering protocol is well-established: methylfolate (5-MTHF, 800mcg-5mg daily), methylcobalamin (B12, 1,000mcg daily), and pyridoxal 5'-phosphate (B6, 25-50mg daily). This combination addresses all three recycling pathways. Betaine (trimethylglycine, 500-3,000mg daily) provides an additional pathway for homocysteine conversion. For MTHFR carriers, methylated forms are essential — folic acid (synthetic) may not convert efficiently. Response is typically seen within 4-8 weeks. If homocysteine remains elevated despite supplementation, investigate kidney function (the kidneys are the primary excretion route).
Testing
Homocysteine is measured from a blood sample. With Helvy, that means a finger-prick kit taken at home and posted to a UKAS-accredited UK laboratory, with results in around 5 days, reviewed by a qualified clinician. Your result is reported against both the clinical range (<15 µmol/L) and the performance-optimal range (<8 µmol/L), so you can see not just whether you are “normal” but whether you are optimal. If you make a change, retest after 8-12 weeks to confirm it worked.
Research
Homocysteine and cardiovascular disease: evidence on causality from a meta-analysis
Wald DS, Law M, Morris JK
BMJ (2002)
DOI: 10.1136/bmj.325.7374.1202Related biomarkers
Related guides
This content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.
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