What is an optimal homocysteine level?
The short answer
Optimal homocysteine is under 9 µmol/L, as stated on video.
Most labs call homocysteine high only above 15. So your report can call 12 normal while it sits above the optimal ceiling.
“I like seeing uric acid below 5, homocysteine below 9 — these are some of the metrics that I'm really looking at consistently.”
“I take these to keep homocysteine below nine.”
What each range means
- under 9 µmol/L Optimal
- 9–15 µmol/L Normal on most reports. Above optimal“I take these to keep homocysteine below nine.” Dr. Peter Attia · 31:22 →
- over 15 µmol/L Most labs flag this as high
What homocysteine measures
An amino acid your body clears using B vitamins.
It builds up when that pathway runs short of folate, B-twelve or B-six. High levels track with cardiovascular and cognitive risk.
Checked against MedlinePlus — Homocysteine Test.
Common questions
What is an optimal homocysteine level?
Under 9 µmol/L, from a quote on video (Dr. Peter Attia, 3:35).
What is a normal homocysteine level?
Most US labs print 5–15 µmol/L. Your report grades you against that range. It exists to catch disease, not to describe your best.
What does your homocysteine number mean?
On a typical lab range, under 5 µmol/L is low, 5 to 15 is normal and over 15 is high. Your own report prints its range next to your number, and that is the one your lab uses. The optimal range on this page comes with the quote behind it.
Is homocysteine of 12 normal?
A typical lab range calls it normal. On video, the optimal ceiling is 9 µmol/L (Dr. Peter Attia, 3:35), so by that line it is high.
What does the homocysteine test measure?
An amino acid your body clears using B vitamins. It builds up when that pathway runs short of folate, B-twelve or B-six. High levels track with cardiovascular and cognitive risk.