What is an optimal homocysteine level?

05915
LAB: NORMAL · 5–15 µmol/LOPTIMAL · 5–9 µmol/L 1 EXPERT

The short answer

An optimal homocysteine level is 5–9 µmol/L. Dr. Peter Attia puts the ceiling at 9. You can watch him say it below.

Most labs call homocysteine high only above 15. So your report can call 12 normal while it sits above where he draws the line.

“I like seeing uric acid below 5, homocysteine below 9 — these are some of the metrics that I'm really looking at consistently.”

Where a number lands, and who said so

  1. under 5 µmol/L Most labs flag this as low
  2. 5–9 µmol/L The range Dr. Peter Attia draws
  3. 9–15 µmol/L Normal on most reports. Above optimal“we typically target eight or nine as the upper limit we want to see, even though the lab reference range says up to 13 or 14 is normal.” Dr. Peter Attia · 1:16:07 →
  4. 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.

One of the doctors we cite, on why it matters

“Our concern is mostly through cardiovascular by the way uh because I think there we have pretty good evidence that homocysteine uh impairs the clearance of two molecules sdma and adma that impair nitric oxide synthase which obviously has an important role in the cardiovascular endothelial World”

Common questions

What is an optimal homocysteine level?

5–9 µmol/L, according to Dr. Peter Attia.

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?

Under 5 µmol/L, your report marks it low. Between 5 and 15 it prints as normal. Over 15, your report marks it high. Where the people we follow draw their own line is above.

Is homocysteine of 12 normal?

Your lab will call it normal. Dr. Peter Attia puts the ceiling at 9 µmol/L, so by that number 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.

Where does this number come from?

Dr. Peter Attia, on video. The link above jumps straight to that minute.

Where else this number comes up