# ALT: The enzyme that shows liver strain

> ALT is the liver enzyme most labs check. See the healthy limit for men and women, what raises ALT, and what to do if yours is high.

- Also called Alanine aminotransferase, SGPT and ALT (SGPT)
- Often on a standard checkup
- Fast for 12 hours
- Web page: https://picardo.health/guides/biomarkers/alt

## The short answer

ALT is an enzyme that leaks out of liver cells when they’re strained or damaged. Gastroenterology guidelines put a healthy level at up to about 33 IU/L for men and 25 for women, which is lower than most lab reports flag.[1][3]

- **A good result:** 33 IU/L or under for men, and 25 or under for women.[1][3] Your report may only flag results above 44 or 32.[8][9]
- **If yours is high:** The most common cause is fat in the liver, which travels with extra weight and high blood sugar. Losing weight brings it down.[2][3]
- **Should you test?** You probably already have; it’s on most checkup blood tests. With diabetes or prediabetes, ask for a FIB-4 score too, because a normal ALT can miss scarring.[2][4]

## What is a normal ALT level?

There are two cutoffs to know. Labcorp flags ALT above 44 IU/L for men and 32 for women.[8][9] European liver guidelines set the healthy limit lower, at 33 for men and 25 for women, and US gastroenterology guidelines put it at 29 to 33 for men and 19 to 25 for women.[1][3] The US liver society says an ALT that stays above 30 can be a sign of liver damage.[2] Labs set their ranges from different groups of people, so treat these limits as a guide rather than a hard line:[1]

Which fits you?

### Man

| Result (IU/L) | What it means |
| --- | --- |
| Under 34 | A healthy ALT |
| 34 to 44 | Normal on your report, but above the healthy limit |
| 45 to 164 | Raised: find the cause |
| 165 or more | High: see a clinician promptly |

### Woman

| Result (IU/L) | What it means |
| --- | --- |
| Under 26 | A healthy ALT |
| 26 to 32 | Normal on your report, but above the healthy limit |
| 33 to 124 | Raised: find the cause |
| 125 or more | High: see a clinician promptly |

### A healthy ALT

**Range:** 33 IU/L or under for men; 25 or under for women.

Your ALT is under the limit liver specialists consider truly healthy.[1] That’s a good sign, but it doesn’t rule out liver disease on its own. ALT can stay normal while fat and scarring build up.[2]

**How worried to be:** Nothing to worry about.

**What to do next:**

1. If you have type 2 diabetes or prediabetes, ask for a FIB-4 score anyway. US diabetes guidelines recommend it even when liver enzymes are normal.[4]
2. Otherwise, check it again with your next routine blood work.

[Test FIB-4, $28.87](https://app.picardo.health/labs/order?tests=403604&ref=guide-alt)

### Normal on your report, but above the healthy limit

**Range:** 34 to 44 IU/L for men; 26 to 32 for women.

Your lab won’t flag this, because its cutoffs are 44 for men and 32 for women.[8][9] But the American College of Gastroenterology says a healthy ALT tops out at 29 to 33 for men and 19 to 25 for women, and that anything higher should be looked into.[1] European guidelines use 33 and 25.[3] The most common cause is extra fat in the liver.[2]

**How worried to be:** Not urgent. Worth raising at your next visit, especially if you have extra weight or diabetes, or drink most days.

**What to do next:**

1. Think about what could be behind it, such as alcohol, extra weight, a hard workout in the weeks before the test or a new medicine or supplement.[1]
2. Recheck it. If it stays raised for more than 6 months, guidelines suggest testing for other liver conditions or seeing a liver specialist.[2][4]
3. With diabetes, prediabetes or extra weight, ask for a FIB-4 score to check for scarring.[2][4]

[Test FIB-4 and HbA1c, $32.87](https://app.picardo.health/labs/order?tests=403604,001453&ref=guide-alt)

### Raised: find the cause

**Range:** 45 to 164 IU/L for men; 33 to 124 for women.

Your ALT is above the lab’s range, but less than 5 times the healthy limit.[1][8][9] This is a common result. Fat in the liver is the usual cause, but alcohol, medicines and supplements, hepatitis B or C and too much iron can all raise it.[1][2]

**How worried to be:** Not an emergency. See a clinician in the next few weeks to find the cause.

**What to do next:**

1. Test for hepatitis B and C, and check your iron. Guidelines recommend these for anyone with a raised ALT.[1]
2. List every medicine and supplement you take, herbal ones included.[1]
3. Stop drinking alcohol while you find the cause.[1]
4. Expect a repeat test, and an ultrasound or a FIB-4 score if fatty liver is likely.[1][2]

[Test hepatitis B and C, iron and ferritin, $30.75](https://app.picardo.health/labs/order?tests=006510,144050,001321,004598&ref=guide-alt)

### High: see a clinician promptly

**Range:** 165 IU/L or more for men; 125 or more for women.

That’s at least 5 times the healthy limit, and guidelines say an ALT this high calls for tests for acute hepatitis as well as the usual causes.[1] Causes include viral hepatitis, a reaction to a medicine or supplement, too much acetaminophen (Tylenol) and poor blood flow to the liver.[1]

**How worried to be:** See a clinician within a day or two. Get emergency care now if you may have taken too much acetaminophen, or if you’re confused or very drowsy. Get care today if your skin or the whites of your eyes turn yellow.[1]

**What to do next:**

1. Take this result to a clinician, with a list of every medicine and supplement you’ve taken in the last few months.[1]
2. Expect tests for hepatitis A, B and C, and a check of how well your liver is making clotting proteins.[1]

## What is ALT?

> Think of ALT as a leak detector. When liver cells are inflamed or damaged, more of it spills into your blood. But a quiet detector doesn’t prove there’s no damage: slow scarring can leak very little.

ALT, short for alanine aminotransferase, is an enzyme made mostly in your liver. A raised level is a sign that liver cells are under strain.[1] It’s more specific to the liver than AST, the other enzyme on your report, which also comes from muscle.[1]

ALT runs higher in men than in women, and rises with body weight.[1]

## What raises ALT?

- Fat in the liver, now called MASLD. It’s very common: more than 30% of adults worldwide have it.[3]
- Alcohol[1]
- Medicines and supplements, including too much acetaminophen and herbal products such as green tea extract[1]
- Hepatitis B and C[1]
- Too much iron, from an inherited condition called hemochromatosis[1]
- Hard exercise or a muscle injury, which raise AST more than ALT[1]
- Less often, autoimmune hepatitis, celiac disease, thyroid problems and Wilson disease[1]

## Can your liver be scarred if your ALT is normal?

Yes. ALT is often normal in people whose fatty liver has already caused serious scarring, so guidelines say it shouldn’t be used on its own to rule that out.[2] US diabetes guidelines recommend a FIB-4 score for adults with type 2 diabetes or prediabetes, even when their liver enzymes are normal.[4]

FIB-4 combines your age, AST, ALT and platelet count into one score:[2][3]

| FIB-4 score | What it means | What usually happens next |
| --- | --- | --- |
| Under 1.3 (under 2.0 if you’re over 65) | Low risk of advanced scarring | Recheck every 1 to 3 years |
| 1.3 to 2.67 (2.0 to 2.67 if you’re over 65) | Can’t tell yet | A liver stiffness scan or an ELF blood test |
| Over 2.67 | High risk of advanced scarring | See a liver specialist |

FIB-4 is less accurate under age 35.[2][3]

## How to lower ALT

- **Losing weight:** Losing 5% of your weight reduces liver fat. 7% to 10% calms inflammation, and 10% or more can start to reverse scarring.[3] How much it helps: a lot. How sure we are: very sure.
- **Cutting back on alcohol:** Alcohol adds to the damage from a fatty liver. If you already have significant scarring, guidelines say stop completely.[2][3] How much it helps: some. How sure we are: fairly sure.
- **Moving more:** At least 150 minutes a week of moderate activity, or 75 minutes of vigorous activity.[3] How much it helps: some. How sure we are: fairly sure.
- **Stopping a supplement that’s behind it:** Some herbal and diet supplements, such as green tea extract, can injure the liver.[1] Ask before stopping a prescribed medicine. How much it helps: a lot. How sure we are: fairly sure.
- **Coffee:** Three or more cups a day goes with less advanced liver disease in studies. That’s a link, not proof.[2] How much it helps: a little. How sure we are: early evidence.
- **Medicines for MASH:** Resmetirom and semaglutide are approved for MASH with moderate to advanced scarring that hasn’t reached cirrhosis, not for a raised ALT on its own.[5][7] How much it helps: a lot. How sure we are: fairly sure.

When fatty liver is the cause, a fall in ALT of 17 IU/L or more during treatment tends to go with less damage on a liver biopsy. It’s less clear how well it tracks scarring.[2]

Two medicines are now FDA-approved for MASH, the inflamed form of fatty liver, once it has caused moderate to advanced scarring but not cirrhosis. Resmetirom (Rezdiffra) was approved in March 2024, and semaglutide (Wegovy) in August 2025.[5][7] In a year-long trial in people with MASH and scarring, MASH cleared without scarring getting worse in 26% to 30% of people on resmetirom, against 10% on placebo.[6] After 72 weeks of semaglutide it cleared in 63%, against 34% on placebo.[5] Both approvals are accelerated. Trials of whether the drugs prevent cirrhosis and liver failure are still running.[5][7]

## Who should get an ALT test?

ALT is part of the comprehensive metabolic panel, so most people get it with routine blood work. It matters most if:

- You have type 2 diabetes or prediabetes.[4]
- You have extra weight along with high blood pressure, high triglycerides or low HDL cholesterol.[3]
- You drink more than about 1½ drinks a day (women) or 2 (men).[2]
- A parent, brother or sister has cirrhosis from fatty liver.[2]
- You take medicines or supplements that can affect the liver.[1]

Testing everyone for fatty liver isn’t recommended. Guidelines focus on people with these risk factors.[2][3]

## How to get an ALT test, and what it costs

It comes from the comprehensive metabolic panel, which costs $4.00 through Picardo. The Heart Health panel adds 16 more tests from the same visit for $150.90.

- **Recommended:** [the Heart Health panel, $150.90](https://app.picardo.health/labs/order?panels=heart-health&ref=guide-alt). 17 tests, fast for 12 hours first. Fatty liver, the most common reason for a raised ALT, travels with high blood sugar and cholesterol. The panel adds GGT, HbA1c, insulin and cholesterol tests, plus a platelet count, the last piece clinicians need to work out a FIB-4 scarring score. [What’s in it](https://picardo.health/guides/panels/heart-health.md).
- [Comprehensive metabolic panel, $4.00](https://app.picardo.health/labs/order?tests=322000&ref=guide-alt). The test this number comes from. Labcorp 322000, fast for 12 hours.

Every order comes with:

- Results in 2 to 3 days, in the app
- Physician follow-up if you want one
- Free Labcorp draw, or $75 at home
- No other fees. HSA and FSA eligible.

It’s also part of the [Base Core Annual – Men](https://picardo.health/labs/panels/base-core-men), [Base Core Annual – Women](https://picardo.health/labs/panels/base-core-women), [Brain Health Screening](https://picardo.health/labs/panels/brain-health), [Pregnancy](https://picardo.health/labs/panels/pregnancy), [Postpartum](https://picardo.health/labs/panels/postpartum), [Fertility](https://picardo.health/labs/panels/fertility), [Thyroid & Autoimmunity](https://picardo.health/labs/panels/thyroid-autoimmunity) and [Celiac / GI](https://picardo.health/labs/panels/celiac-gi) panels, if you want a wider checkup.

Already have a result? [Ask Picardo about it](https://app.picardo.health/auth).

## Questions people ask

### Is an ALT of 40 bad?

It depends on your sex. For a man, 40 is inside Labcorp’s range but above the healthy limit of 33. For a woman, it’s above both.[1][8][9] It’s worth finding out why, but it’s rarely urgent.

### Can exercise raise ALT?

Yes. Hard exercise and muscle injuries can raise ALT, though they usually raise AST more.[1] If you lifted weights or trained much harder than usual in the weeks before your test, mention it, because it can explain a raised result.

### Do statins raise ALT?

Sometimes, a little. Serious liver injury from statins is rare, and US liver specialists say statins are safe for people with fatty liver, including those with cirrhosis that hasn’t caused complications.[1][2] Don’t stop one over a mildly raised ALT without asking the clinician who prescribed it.

### Is fatty liver the same as MASLD?

Mostly. In 2023, liver societies renamed nonalcoholic fatty liver disease (NAFLD) as metabolic dysfunction-associated steatotic liver disease (MASLD). The name points at the cause. It means extra fat in the liver alongside at least one sign of metabolic trouble, such as extra weight, high blood sugar, high blood pressure or high triglycerides. Fatty liver from heavy drinking, some medicines or rarer causes has other names.[3]

### What’s the difference between ALT and AST?

Both are enzymes that leak from damaged liver cells. ALT comes mostly from the liver, so it’s the more specific of the two. AST is also in muscle and the heart.[1] When AST is much higher than ALT, alcohol or muscle is a common reason.[1]

## Often checked alongside

- [AST](https://picardo.health/guides/biomarkers/ast.md): An enzyme from liver and muscle
- [GGT](https://picardo.health/guides/biomarkers/ggt.md): A liver enzyme that rises with alcohol
- [ALP](https://picardo.health/guides/biomarkers/alp.md): An enzyme from liver and bone
- [HbA1c](https://picardo.health/guides/biomarkers/hba1c.md): Average blood sugar over three months

## Test details

- **Labcorp test:** Metabolic Panel (14), Comprehensive, 322000
- **LOINC:** 1742-6
- **Sample:** Blood
- **Fasting:** Not needed for ALT itself. The metabolic panel it comes on asks for 12 hours, for its glucose result.
- **Typical lab range:** 0 to 44 IU/L (men); 0 to 32 IU/L (women)[8][9]
- **Healthy limit:** 33 IU/L or under (men); 25 or under (women)[1]
- **Units:** IU/L, the same as U/L

## Sources

1. Kwo PY, Cohen SM, Lim JK. ACG clinical guideline: evaluation of abnormal liver chemistries. Am J Gastroenterol. 2017;112(1):18–35. https://doi.org/10.1038/ajg.2016.517
2. Rinella ME, Neuschwander-Tetri BA, Siddiqui MS, et al. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology. 2023;77(5):1797–1835. https://doi.org/10.1097/HEP.0000000000000323
3. European Association for the Study of the Liver (EASL), European Association for the Study of Diabetes (EASD), European Association for the Study of Obesity (EASO). EASL–EASD–EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD). J Hepatol. 2024;81(3):492–542. https://doi.org/10.1016/j.jhep.2024.04.031
4. American Diabetes Association Professional Practice Committee for Diabetes. 4. Comprehensive medical evaluation and assessment of comorbidities: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S61–S88. https://doi.org/10.2337/dc26-S004
5. Bansal MB, Patton H, Morgan TR, et al. Semaglutide therapy for metabolic dysfunction-associated steatohepatitis: November 2025 updates to AASLD Practice Guidance. Hepatology. 2026;83(5):1326–1340. https://doi.org/10.1097/HEP.0000000000001608
6. Harrison SA, Bedossa P, Guy CD, et al. A phase 3, randomized, controlled trial of resmetirom in NASH with liver fibrosis. N Engl J Med. 2024;390(6):497–509. https://doi.org/10.1056/NEJMoa2309000
7. US Food and Drug Administration. FDA approves first treatment for patients with liver scarring due to fatty liver disease [news release]. March 14, 2024. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-patients-liver-scarring-due-fatty-liver-disease
8. Labcorp. Alanine aminotransferase (ALT/SGPT), test 001545: sample report. Labcorp test menu. Accessed October 28, 2026. https://files.labcorp.com/testmenu-d8/sample_reports/001545.pdf
9. Labcorp. FIB-4, test 403604: sample report (female patient). Labcorp test menu. Accessed October 28, 2026. https://files.labcorp.com/testmenu-d8/sample_reports/403604.pdf

Updated 2026-10-28. This is general health information, not medical advice: talk to your clinician about your results and before changing any treatment.