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Marker · Ranges for learning, not a diagnosis

Homocysteine

Also called tHcy.

An amino acid the body clears using folate, B12 and B6. Blood levels fall when you take those vitamins, if a shortage of them was the problem.

Read this first

  • Coach, not doctor. Aaron Cuha is a coach, not a doctor. No medical credential is claimed for him, or for these pages. A number on a blood test is something to talk over with a doctor, not something to diagnose yourself with. Nothing here is a prescription, a plan to follow, or a reason to start or stop a medicine. Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.
  • Knowledge stays free. Knowledge stays free. Every page, every guide and every tool is free to read and stays free. No partner paid for a place on these pages.
  • Three kinds of lab page, kept apart. /bloodwork is blood tests for people. /testing and /prices/labs are lab tests on peptide vials. /supplements/quality is what is in the bottle.

Why a longevity audience asks

The owner's rule for methylated B vitamins waits on homocysteine, and only alongside MTHFR gene results. Large studies then showed that lowering homocysteine with B vitamins did not prevent heart attacks or strokes. Moving the number is not the same as changing what happens to you.

How a coach reads it

Many labs flag about 15 umol/L and above. Some doctors prefer the low teens or under 10. Those are ranges to discuss. The HOPE-2 and NORVIT studies lowered the number, and people did not get the drop in heart attacks and strokes everyone expected. This is not a diagnosis.

Units on this page: umol/L

When it is low

Usually not a target. Very low numbers are rare and not a reason to add more B vitamins.

When it is high

Can mean low folate or B12, kidney disease, or a gene difference. Check B12 with an MMA test before you celebrate a B-complex. The MTHFR gene is background, not a plan.

Easy ways to misread it

  • Lowering homocysteine is easy. In the large studies, preventing heart attacks and strokes was not.
  • Do not treat a high number with folate alone if B12 has not been checked. That can hide a B12 shortage.

What to ask your doctor

Ask for homocysteine with B12, MMA and folate. MTHFR gene testing is optional background, not a shopping list.

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Sources on this page