Aspartate Aminotransferase

Liver Function marker

AST

Aspartate Aminotransferase

Category: Liver Function
Unit: U/L

Enzyme found in liver, heart, and muscles. Elevated by liver damage or muscle breakdown.

PED Notes

Both liver stress and heavy training elevate AST. Post-workout AST can be 2-3x normal. When AST is elevated but ALT is normal, it often indicates muscle damage rather than liver issues. Oral AAS will elevate both. Key diagnostic tip: if AST is high but ALT and GGT are normal, it is almost certainly muscle damage from training -- not liver stress.

When high

Differential first (before intervention):

  • Isolated AST elevation with normal ALT and GGT usually reflects muscle damage from training, not liver stress; rest 48-72h and retest
  • AST + ALT + GGT all elevated confirms hepatic origin

Supplements (hepatic origin):

  • TUDCA -- 500-1000mg/day (with meals); bile flow and hepatoprotection
  • NAC -- 1200-1800mg/day (empty stomach, divided doses); glutathione precursor
  • Milk Thistle / Silymarin Phytosome (Siliphos) -- 200mg 2x/day (~10x absorption vs standard silymarin)
  • Alpha-Lipoic Acid (ALA) -- 300-600mg/day

Compound/AAS adjustments:

  • Switch oral AAS to injectable equivalents -- single most effective intervention for drug-induced hepatic AST elevation
  • Drop 17-alpha-alkylated orals if enzymes persistently >3x ULN or bilirubin rises
  • Proviron (mesterolone) is NOT 17-aa and does not meaningfully stress the liver
  • Zero alcohol during oral AAS cycles

Pharmacological options (severe or cholestatic elevation):

  • Ursodeoxycholic acid (UDCA / Actigall) -- 10-15mg/kg/day (typically 500mg 2x/day); prescription; more potent than TUDCA for confirmed cholestatic injury; physician-supervised

Lifestyle:

  • Rest 48-72h before blood draw for accurate liver assessment

AST rises with muscle damage as well as liver stress, and telling them apart changes what you do next: Liver enzymes on steroids: how to read your ALT, AST and GGT.

Educational information, not medical advice. Nothing here is a prescription or a treatment plan, and it does not account for your history, medications or conditions. Use it to ask better questions: bring it to your doctor and decide together. Full disclaimer.

History Chart

Reading History

Frequently Asked Questions

Reference Ranges

Standard Range

0 - 40 U/L

VitalMetrics Range

0 - 60 U/L

Statistics