Biomarkers · Chemical
AST
An AST blood test measures the amount of AST in your blood. This test is commonly used to help diagnose liver damage or disease.
AST, or aspartate aminotransferase, is an enzyme found mainly in the liver but also in the heart, muscles, and other tissues. When liver cells or other cells that contain AST are damaged, they release the enzyme into the blood.
- Also listed as
- aspartate aminotransferase, sgot, aspartate transaminase, AST P5P
- Primary unit
- IU/L
- LOINC codes
- 30239-8, 1920-8
- Tests that measure AST
- Labcorp 22, Quest Diagnostics 21
See why clinicians order the test
Clinicians commonly order the AST test to help diagnose liver damage or liver disease.
Goal: Liver health
The test often appears in routine blood screening that checks the health of the liver.
Goal: Liver health
Clinicians use the test during routine checkups and to monitor the treatment of a liver problem.
Goal: Liver health
Clinicians may order the test even without symptoms when a person has a higher chance of developing liver disease.
Goal: Liver health
Read with companion markers
Bilirubin ranks among the most common liver chemistries that clinicians order together with AST, ALT, and alkaline phosphatase.
Clinicians compare alkaline phosphatase with AST, since a disproportionate alkaline phosphatase rise over AST and ALT defines cholestatic injury.
Clinicians read AST with ALT because a disproportionate rise in both, compared with alkaline phosphatase, defines hepatocellular injury.
Check what can shift results
Prepare for the test
- People usually need to fast, with no eating or drinking, for up to 12 hours before these blood tests.
- Some medicines may need to be stopped before the test, so patients should tell their provider about everything they take.
- MedlinePlus advises against stopping any medicine unless the provider gives that instruction.
Each statement links to the source we wrote it from. Last updated October 19, 2026.
Ranges
Compare the reference ranges labs publish with guideline targets, diagnostic cut-offs, study-based ranges and practitioner targets. Move across the rows to check a value against each range, and open a source from the legend. How to read these ranges
All 2 published ranges, with sources
Lab reference ranges
Quest, men 20 to 4910 to 40 U/L
Men 20 to 49
Quest Diagnostics Test Directory, Aspartate Aminotransferase (AST) (822), 2025
Quest, women 20 to 4410 to 30 U/L
Women 20 to 44
Quest Diagnostics Test Directory, Aspartate Aminotransferase (AST) (822), 2025
Tests
Check the catalog code, specimen, method and preparation for every test that measures AST. Select up to five tests to compare them side by side.
Labcorp 22 tests
Single-analyte tests
Aspartate Aminotransferase (AST/SGOT) 001123
Serum · Fasting not stated · Turnaround Within 1 day
Labcorp catalog pageMethod and collection
- Method
- Kinetic
- Collection
- Separate serum or plasma from cells within 45 minutes of collection.
Panels that include this biomarker
APRI With Reflex to NASH FibroSure® Plus 402171
3 analytes · Serum · Fasting not stated · Turnaround 1 - 5 days
Labcorp catalog pageMethod and collection
- Method
- See individual test components.
- Preparation
- Patient should be fasting for at least eight hours.
- Collection
- Serum : Separate from cells within 45 minutes of collection. Whole blood : Invert EDTA tube immediately 8 to 10 times once tube is filled at the time of collection.
AST and Platelets with APRI 385375
3 analytes · Serum · Fasting not stated · Turnaround Within 1 day
Labcorp catalog pageMethod and collection
- Method
- AST: kinetic; Platelet Count: automated cell counter
- Collection
- Separate serum from cells within 45 minutes of collection; invert EDTA tube immediately 8 to 10 times once tube is filled at the time of collection.
FIB-4 403604
4 analytes · Serum · Fasting not stated · Turnaround Within 1 day
Labcorp catalog pageMethod and collection
- Method
- AST and ALT: Kinetic Platelet Count: Automated cell counter
- Collection
- Separate serum or plasma from cells within 45 minutes of collection; invert EDTA tube immediately 8 to 10 times once tube is filled at time of collection.
- Reference notes
- 0 – 1.29: low risk for advanced liver fibrosis 1.30 – 2.67: Indeterminate risk for advanced liver fibrosis >2.67: high risk for advanced fibrosis and for developing of other liver-related events
FIB-4 With Reflex to Enhanced Liver Fibrosis (ELF)™ 402175
4 analytes · Serum · Fasting not stated · Turnaround 3 - 6 days
Labcorp catalog pageMethod and collection
- Method
- AST and ALT: kinetic Platelet Count: automated cell counter ELF Reflex if performed: The ELF™ test consists of three fully automated, two-site sandwich immunoassays using direct chemiluminometric technology. The component assays use two monoclonal mouse antibodies: The first antibody is an acridinium ester-labeled antibody. The second antibody is a biotin-labeled antibody. The solid phase contains streptavidin-coated paramagnetic particles. The ELF™ score is derived from an algorithm that combines PIIINP, TIMP-1, and HA. ELF™ is a trademark of Siemens Healthcare Diagnostics.
- Collection
- Serum : Separate from cells within 45 minutes of collection. Whole blood : Invert EDTA tube immediately 8 to 10 times once tube is filled at the time of collection.
FIB-4 With Reflex to NASH FibroSure® Plus 402146
4 analytes · Serum · Fasting not stated · Turnaround Within 1 day
Labcorp catalog pageMethod and collection
- Method
- See individual test components.
- Preparation
- Patient should be fasting for at least eight hours.
- Collection
- Serum : Separate from cells within 45 minutes of collection. Whole blood : Invert EDTA tube immediately 8 to 10 times once tube is filled at the time of collection.
Quest Diagnostics 21 tests
Single-analyte tests
Aspartate Aminotransferase (AST) 822
Serum · Fasting not stated · Turnaround Set up: Mon-Sat; Report available: 3 days
Quest Diagnostics catalog pageMethod and collection
- Method
- Spectrophotometry (SP)
- Reference notes
- Male (U/L) | Female (U/L) <28 days | 3-51 | 3-49 28 days-11 months | 3-65 | 3-79 1-3 years | 3-56 | 3-69 4-6 years | 20-39 | 20-39 7-19 years | 12-32 | 12-32 20-49 years | 10-40 20-44 years | | 10-30 ≥45 years | | 10-35 ≥50 years | 10-35
Panels that include this biomarker
FIB-4 Index Panel with Reflex to Enhanced Liver Fibrosis (ELF) Score 12734
4 analytes · Serum · Fasting not stated
Quest Diagnostics catalog pageMethod and collection
- Method
- Electronic Cell Sizing/Counting/Cytometry/Microscopy • Spectrophotometry (SP)
- Reference notes
- See Laboratory Report
Liver Fibrosis, Fibrosis-4 (FIB-4) Index Panel 30555
4 analytes · Serum · Fasting not stated
Quest Diagnostics catalog pageMethod and collection
- Method
- Spectrophotometry (SP) • Electronic Sizing and Counting/Cytometry/Microscopy
- Collection
- Note: If drawn with lead testing, EDTA (tan-top) is required
- Reference notes
- See Laboratory Report
Hepatic Function Panel without Total Protein 34391
7 analytes · Serum · Fasting not stated
Quest Diagnostics catalog pageMethod and collection
- Method
- See individual tests
NAFLD Fibrosis Score 91979
7 analytes · Serum · Fasting not stated
Quest Diagnostics catalog pageMethod and collection
- Method
- Spectrophotometry (SP) • Electronic Sizing and Counting/Cytometry/Microscopy
- Preparation
- Fasting preferred. Fasting is defined as no consumption of food or beverage other than water for at least 8 hours before testing.
- Collection
- For risk calculations to be performed, the following patient-specific information must be provided at the time of order: Age: Years Gender: M (for male) or F (for female) Height Feet: Feet Height Inches: Inches Weight: lbs. Diabetes Status: Y (for yes) or N (for no)
- Reference notes
- See Laboratory Report
Hepatic Function Panel 10256
10 analytes · Serum · Fasting not stated · Turnaround Set up: Mon-Sat; Report available: 3 days
Quest Diagnostics catalog pageMethod and collection
- Method
- See individual tests
- Collection
- Administration of STRENSIQ may interfere in certain assays and may falsely elevate values. For patients receiving STRENSIQ, consideration should be given to using alternate methods.
- Reference notes
- See Laboratory Report
0 of 5 tests selected
Pick one moreGoals and conditions
We link AST to these goals and conditions from named guidelines and studies.
Liver healthGoal, primary marker
The ACG guideline names AST among the most commonly ordered liver chemistries.
Hereditary hemochromatosisCondition, ICD-10 E83.110, companion marker
AASLD recommends liver biopsy when liver enzymes such as AST are raised.
Metabolic dysfunction-associated steatotic liver disease (MASLD)Condition, ICD-10 K76.0, primary marker
AASLD uses AST with ALT, age and platelets to calculate the FIB-4 fibrosis score.
Sources
Check the guidelines, studies and lab catalogs behind every range and link on this page. Open a source to see each claim it backs.
Clinical guidelines
AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease
American Association for the Study of Liver Diseases, 2023
Linked to Metabolic dysfunction-associated steatotic liver disease (MASLD) (primary)
AASLD uses AST with ALT, age and platelets to calculate the FIB-4 fibrosis score.
ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries
American College of Gastroenterology, 2017
Read together with
Clinicians compare alkaline phosphatase with AST, since a disproportionate alkaline phosphatase rise over AST and ALT defines cholestatic injury.
“Cholestatic injury is defined as disproportionate elevation of alkaline phosphatase level as compared with AST and ALT levels.”
Read together with
Clinicians read AST with ALT because a disproportionate rise in both, compared with alkaline phosphatase, defines hepatocellular injury.
“Hepatocellular injury is defined as disproportionate elevation of AST and ALT levels compared with alkaline phosphatase levels.”
Read together with
Bilirubin ranks among the most common liver chemistries that clinicians order together with AST, ALT, and alkaline phosphatase.
“The most common liver chemistries ordered are serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and bilirubin.”
Linked to Liver health (primary)
The ACG guideline names AST among the most commonly ordered liver chemistries.
Read together with
Clinicians commonly order AST alongside bilirubin as part of the standard liver chemistries.
Read together with
Clinicians compare AST with ALP, because a disproportionate rise in AST and ALT relative to ALP defines hepatocellular injury.
Diagnosis and management of hemochromatosis: 2011 practice guideline by the American Association for the Study of Liver Diseases
American Association for the Study of Liver Diseases, 2011
Linked to Hereditary hemochromatosis (companion)
AASLD recommends liver biopsy when liver enzymes such as AST are raised.
Lab catalogs
Quest Diagnostics Test Directory, Aspartate Aminotransferase (AST) (822)
2025
Lab reference range: Quest, men 20 to 49, 10 to 40 U/L
Lab reference range: Quest, women 20 to 44, 10 to 30 U/L
Retrieved October 12, 2025
Labcorp test menu
Labcorp
Test catalog: 22 tests, with codes, specimens, methods and reference intervals
Quest Diagnostics test menu
Quest Diagnostics
Test catalog: 21 tests, with codes, specimens, methods and reference intervals
Reference sources
ALT Blood Test
MedlinePlus, National Library of Medicine
Read together with
Labs usually measure ALT together with AST, another liver enzyme, as part of a liver function panel.
Retrieved October 19, 2026
AST Test
MedlinePlus, National Library of Medicine
Before the test
MedlinePlus advises against stopping any medicine unless the provider gives that instruction.
“But don't stop taking any medicines unless your provider tells you to.”
Before the test
Some medicines may need to be stopped before the test, so patients should tell their provider about everything they take.
“You may need to stop taking certain medicines before the test, so tell your provider about everything you take.”
Before the test
People usually need to fast, with no eating or drinking, for up to 12 hours before these blood tests.
“You usually need to fast (not eat or drink) for up to 12 hours before these tests.”
Reasons to test
Clinicians use the test during routine checkups and to monitor the treatment of a liver problem.
“You may get an AST blood test as part of your routine checkup or to monitor the treatment of a liver problem.”
Reasons to test
Clinicians commonly order the AST test to help diagnose liver damage or liver disease.
“This test is commonly used to help diagnose liver damage or disease.”
Reasons to test
The test often appears in routine blood screening that checks the health of the liver.
“An AST blood test is often part of a routine blood screening to check the health of your liver.”
Reasons to test
Clinicians may order the test even without symptoms when a person has a higher chance of developing liver disease.
“Even if you don't have symptoms, your health care provider may order an AST blood test if you're more likely to develop liver disease because of:”
What can shift results
Pregnancy, exercise, age, and sex are among the many factors that can affect AST results.
“Many things can affect your results, such as pregnancy, exercise, certain medicines, and your age or sex.”
What can shift results
Certain medicines are among the many factors that can affect AST test results.
“Many things can affect your results, such as pregnancy, exercise, certain medicines, and your age or sex.”
What can shift results
Damage to cells outside the liver that contain AST also releases the enzyme into the blood.
“When your liver or other cells that contain AST are damaged, they release AST into your blood.”
What it reflects
When liver cells or other cells that contain AST are damaged, they release the enzyme into the blood.
“When your liver or other cells that contain AST are damaged, they release AST into your blood.”
What it reflects
AST, or aspartate aminotransferase, is an enzyme found mainly in the liver but also in the heart, muscles, and other tissues.
“It is found mainly in your liver but also in your heart, muscles, and other tissues.”
Retrieved October 19, 2026
Codes and registries
Regenstrief Institute codes that identify the same result across labs.
Search ClinicalTrials.gov for AST
Registered studies that measure AST, on the U.S. National Library of Medicine registry.
Verify these ranges and sources
We compile this page from named laboratory catalogs, guidelines and studies. Labs calculate reference intervals from the people they test, for one assay method and one population group, so an interval describes that population rather than an optimal target.
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