What is an optimal AST level?
The short answer
Optimal AST is under 30 U/L, as stated on video.
Most labs call AST high only above 40. So your report can call 35 normal while it sits above the optimal ceiling.
“now the general rule of thumb is that you would like to see an A and ALT both below about 30 IU per liter”
What each range means
- under 30 U/L Optimal
- 30–40 U/L Normal on most reports. Above optimal Dr. Peter Attia · 17:32 →
- over 40 U/L Most labs flag this as high
What AST measures
An enzyme found in your liver, but also in muscle and heart tissue.
Paired with ALT, it separates liver strain from muscle damage. Hard exercise alone can raise it.
Checked against MedlinePlus — AST Test.
Why it matters, on the record
“these are enzymes made by the pyes that are released into plasma when the liver is stressed so as you see more alt and a that indicates more stress”
Common questions
What is an optimal AST level?
Under 30 U/L, from a quote on video (Dr. Peter Attia, 17:32).
What is a normal AST level?
Most US labs print 0–40 U/L. Your report grades you against that range. It exists to catch disease, not to describe your best.
What does your AST number mean?
On a typical lab range, up to 40 U/L is normal and over 40 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 AST of 35 normal?
A typical lab range calls it normal. On video, the optimal ceiling is 30 U/L (Dr. Peter Attia, 17:32), so by that line it is high.
What does the AST test measure?
An enzyme found in your liver, but also in muscle and heart tissue. Paired with ALT, it separates liver strain from muscle damage. Hard exercise alone can raise it.