What Homocysteine measures
Homocysteine is an intermediate in methionine metabolism. When remethylation or transsulfuration support is weaker than expected, homocysteine can rise instead of being recycled efficiently.
Why this marker matters
It is useful because it turns a genetic hypothesis about folate, B12, or methylation support into something you can actually measure. It is not specific on its own, but it is often a strong first-pass validation marker.
When to check it
- when MTHFR, BHMT, CBS, or related methylation genes look relevant
- when fatigue, brain fog, or poor supplement response keeps recurring
- when folate and B12 support questions are still unresolved
How to interpret it
- higher values can indicate methylation support is under strain
- interpret it together with folate, B12, and symptom context
- do not treat one lab value as a diagnosis by itself
Where it fits in DNA follow-up
Homocysteine is often the clearest bridge between DNA-based methylation hypotheses and real follow-up testing.
Example interpretation
Your folate-processing pathway may deserve follow-up because homocysteine is a practical marker of whether methylation support is actually pressured.
Suggested companion markers: serum B12 and folate status.