AST is an enzyme blood test that helps check liver and muscle health.
Aspartate aminotransferase (AST) is an enzyme found in the liver but also in the heart, muscles, and red blood cells. It helps cells turn protein into energy.
When these tissues are damaged, AST leaks into the blood. Because it is not unique to the liver, it is read alongside ALT to tell where the problem lies.
A raised AST can reflect liver damage, but it can also come from the heart or muscles after exertion or injury. When AST and ALT rise together, the liver is usually the source.
The ratio of AST to ALT is a useful clue. A ratio above two often points to alcohol related liver disease, while a lower ratio is more typical of other liver problems.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
| Group | Serum AST (SI) |
| Men | up to ~50 U/L |
| Women | up to ~35 U/L |
Ranges are guidance only and vary by lab, assay, and sex. Many German labs follow IFCC standardised limits. Read your result against your own lab's reference interval, in line with DGKL practice.
Intense exercise, a muscle injury, or a recent heart event can raise AST without any liver problem. Haemolysis of the blood sample falsely raises it, since red cells contain AST. Many medicines affect the result. No fasting needed.
Best read with ALT (and the AST to ALT ratio), GGT, and alkaline phosphatase when looking at liver health.
What does an AST result mean in plain terms? It shows how much of this enzyme is in your blood. Higher levels can reflect liver or muscle stress and guide next steps.
Do I need to fast for an AST test? No. Fasting is not required for AST. Testing at rest gives the most stable result.
What can temporarily raise AST? Hard workouts, muscle injury, alcohol, and some medicines or supplements can raise AST for a short time.
How often should I test AST? Your clinician may repeat it in weeks to confirm changes, or monitor it regularly if you take liver‑affecting medicines.
How long do results take? Results are usually ready in about 7 days.
What should I discuss with my clinician? Share your medicines, supplements, alcohol use, recent exercise, and any symptoms. Ask if more liver tests are needed.
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