AST

Aspartate aminotransferase (AST) is an enzyme found in the liver but also in muscle, heart, and red blood cells. It is less liver-specific than ALT and is interpreted alongside it.

AST complements ALT: the pattern between them is informative. An AST-to-ALT ratio above 2, for example, points toward alcohol-related liver injury, while AST elevation without ALT may reflect muscle rather than liver.

1. 1

   FoundationMetabolic HealthThe best place to understand the major drivers of metabolic disease.
2. 2

   ConditionMASLD / MASHMetabolic fatty liver disease
3. 3

   Signal RecordSemaglutideGLP-1 Receptor Agonist
4. 4

   Body SystemMetabolismEnergy, blood sugar, and how the body processes fuel.

1. Measure it
2. Understand your result
3. See what raises and lowers it
4. Apply evidence-based interventions
5. Recheck on your review cadence

An orientation to how this topic is typically approached — not medical advice.

AST is read as a ratio with ALT and in context. AST > ALT suggests alcohol-related or advanced liver disease (or a muscle source); ALT > AST is more typical of fatty liver. Isolated AST elevation prompts a check for muscle causes.

• Part of a liver panel (LFTs)
• Interpreted with ALT (AST:ALT ratio)

AST is a validated liver-panel component whose value comes largely from its pattern with ALT; its lower liver specificity is well established.

• AASLD and ACG guidance on interpreting liver chemistries

Sources are named authoritative guidelines and scientific bodies. Biomarker pages present established clinical context; calibrated evidence verdicts on specific interventions live in the linked Signal Records.