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ALT (Alanine Aminotransferase)

ALT value: how to read your result

What is ALT exactly? It is an enzyme that sits mainly in the liver, in full alanine aminotransferase. If it is in your blood, liver cells have been damaged. In men anything under 45 u/l is normal, in women under 34. Do you see a number like 14, 16 or 22? That sits comfortably inside the normal ALT value. A mildly raised number is common and has several causes. Usually that is no reason to panic, but it is a reason to look further.

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Reference Ranges

See the value that applies to you:

Age years

Choose male or female — this range differs by sex.

Enter your age — this range changes with age.

This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.

Your reference range

u/l

8 71 u/l

Reference ranges by group, in u/l
Sex	Age	Reference range (u/l)	Relative scale
Male	· 1–5 years	9–35 u/l	9 35
Male	· 6–12 years	10–35 u/l	10 35
Male	· 13–18 years	9–42 u/l	9 42
Male	· 19–50 years	13–71 u/l	13 71
Male	· 51–65 years	13–64 u/l	13 64
Male	· 66–80 years	11–54 u/l	11 54
Male	· 81 years and older	9–42 u/l	9 42
Female	· 1–5 years	10–33 u/l	10 33
Female	· 6–12 years	9–33 u/l	9 33
Female	· 13–18 years	8–35 u/l	8 35
Female	· 19–50 years	9–44 u/l	9 44
Female	· 51–65 years	11–52 u/l	11 52
Female	· 66–80 years	10–46 u/l	10 46
Female	· 81 years and older	8–37 u/l	8 37

8 71 u/l

Source: NVKC Reference population: Nederlandse huisartsenpopulatie (NUMBER, n=7.574.327)

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

Check your own value

ALT (Alanine Aminotransferase): what this test measures

What does ALT mean in a blood test exactly? The test counts how much of this enzyme is in your blood. The result is given in units per litre, or u/l.

The enzyme belongs inside your liver cells. There it does its work converting protein building blocks. As long as those cells are intact, the enzyme stays neatly inside.

If a cell breaks down, the enzyme leaks out. That is how ALT ends up in your bloodstream.

The word "mainly" matters here. ALT sits mainly in the liver and far less anywhere else. That makes it a good liver value. AST, by contrast, sits in many tissues at once, including your muscles. A high AST can therefore simply come from exercise.

Below you can see roughly what the numbers mean. Note: your own lab prints its own limit, and that is the one that counts.

ALT (u/l)	Men	Women
10 to 20	Normal	Normal
21 to 34	Normal	Normal, upper half
35 to 45	Normal, upper half	Mildly raised
46 to 135	Mildly to moderately raised	Mildly to moderately raised
Above 450	Strongly raised	Strongly raised

Your report usually also carries gamma-GT and alkaline phosphatase. Those come from your bile ducts instead of the liver cell. Together they decide which further investigation makes sense.

ALT (Alanine Aminotransferase): why this value matters

Most people arrive here with one question. My ALT is 52, is my liver damaged?

The honest answer is: probably not seriously. But it is worth knowing where it comes from. Below are the causes in order of how often they occur.

Fatty liver comes first. In the Netherlands that is by far the most common reason for a mildly raised result. The rise then usually stays limited, roughly one to three times the upper limit. It also varies between measurements.

Next come medicines and supplements. Paracetamol in overdose counts, as do some antibiotics. Among supplements it is often high-dose green tea extract.

Third is heavy alcohol use. Alcohol usually shifts the ratio with AST as well.

Only then come the things people think of first. Viral hepatitis produces a strongly raised result, many times the upper limit. Hepatitis B and hepatitis C are established with separate blood tests, not with this enzyme.

There is something else that appears almost nowhere. The limit of 45 and 34 comes from the average population. Among screened blood donors the healthy limit sat near 30 for men and 19 for women. A high ALT value by that research can therefore be called "normal" on your report.

The reverse matters too. A normal result does not rule out fatty liver. Many people with proven fatty liver have enzymes within the limits.

ALT (Alanine Aminotransferase): when is testing worthwhile?

ALT is a standard part of a liver panel. Your GP requests such a panel for symptoms that fit the liver. It is also routine when monitoring medicines. And it belongs in a general health check.

There is one preparation that genuinely matters. Do not exercise heavily or unusually in the 48 to 72 hours beforehand. A first gym session or a half marathon can lift your result.

You do not need to fast for this measurement. Useful though: have blood drawn on an ordinary day, not after a party.

One measurement says less than two. Enzyme values fluctuate from week to week. If a number is the same after a few weeks, you know more.

Does a raised result come back? A second isolated ALT rarely follows. The rest gets looked at: AST, gamma-GT and alkaline phosphatase. In athletes CK is sometimes measured too, to rule out muscle.

Always discuss abnormal ALT values with your GP.

ALT (Alanine Aminotransferase): symptoms of a high or low value

Low Levels

You do not notice a low ALT value and you do not need to fix it. There is no illness that starts with a low ALT.

Do you see 8, 10 or 12? That is simply a low normal result. It means little enzyme is leaking from your liver cells, which is exactly the idea.

There is one edge case. ALT needs vitamin B6 to work. With a serious deficiency the test measures less than is actually released. That mainly applies with long-term alcohol use or poor nutrition.

Your muscle mass also counts a little. Someone with little muscle sits somewhat lower on average. So look mainly at your own trend over the years.

High Levels

You usually do not feel raised values. That is exactly why blood is drawn. Your liver rarely complains, certainly not at the start.

If you do notice something, it is vague. Tiredness, less appetite and nausea come first. Sometimes a nagging feeling in the upper right of your abdomen.

There is one list you should not ignore. Yellow eyes or yellow skin, dark urine and unusually pale stools belong together. Itching without a rash belongs there too. Take that to a doctor, and do not wait.

Otherwise the height decides how quickly it matters. Up to roughly three times the upper limit is usually repeating and looking further. Above ten times the upper limit you want to see a doctor quickly.

Not sure? Then simply call your GP. That is what they are there for.

ALT (Alanine Aminotransferase): what to do about an abnormal value

Male

If Low

Normal ALT indicates healthy liver function. Maintain a balanced diet and moderate alcohol consumption.

If High

Elevated ALT may indicate liver cell damage. Consider reducing alcohol intake, reviewing medications, and consulting your healthcare provider for liver evaluation.

Female

If Low

Normal ALT indicates healthy liver function. Maintain a balanced diet and moderate alcohol consumption.

If High

Elevated ALT may indicate liver cell damage. Consider reducing alcohol intake, reviewing medications, and consulting your healthcare provider for liver evaluation.

ALT (Alanine Aminotransferase): lifestyle and this value

There is no pill that brings your ALT down quickly. What does work takes time and is boring but effective.

Number one is weight, and abdominal fat above all. Fatty liver is the most common reason for a mildly raised result. Losing roughly seven percent of your body weight usually brings the value down clearly. Expect months.

Number two is drinking. Heavy alcohol use burdens your liver directly. A few weeks without alcohol often shows how much it was contributing.

Number three is sugar, especially liquid sugar. Soft drinks and fruit juice deliver fructose, and that goes straight to your liver. Water and coffee are simply better here.

Movement counts even without weight loss. Regular walking or cycling already improves your insulin sensitivity.

Go through your supplements with your GP or pharmacist. Herbal preparations really do belong there. And never stop a prescribed medicine yourself because of a blood result. Discuss it first.

ALT (Alanine Aminotransferase): frequently asked questions

How high may your ALT value be?

In men anything under 45 u/l is normal. In women the limit is 34 u/l. Your own laboratory prints its limit on the report, and that is the one that counts. Children have different values by age. A number just above the limit is usually not serious.

Is an ALT value of 16 normal?

Yes, that is a perfectly normal result. The same applies to 14, 15, 19 and 22. Those numbers sit comfortably inside the limit for both men and women. There is then no reason to do anything. Do keep the result, so you can compare later.

How do I bring my ALT down?

Not with a supplement or a detox cure. What works is losing abdominal fat, less alcohol and less liquid sugar. Losing about seven percent of your weight helps most here. That takes months. If the result stays high, go to your GP.

Which liver values are dangerous?

The higher the number, the sooner it needs attention. Up to roughly three times the upper limit is usually repeating and looking further. Above ten times the upper limit, a doctor should look at it quickly. Yellow eyes, dark urine or confusion always make it urgent.

Can a raised ALT value fall on its own?

Yes, that happens regularly. A temporary cause such as a virus, a hard workout or a course of antibiotics passes. Fatty liver also responds to lifestyle, only more slowly. That is why a repeat measurement is often done before further investigation follows.

Do I need to fast for an ALT measurement?

No, fasting is not needed for this measurement. If glucose or lipids are on your request as well, fasting may be asked. More important is that you have not exercised heavily in the 48 to 72 hours beforehand.

Test Products

This marker is included in the following test panels.

InsideTracker

An InsideTracker blood test with 35 biomarkers: heart, hormones, metabolism, inflammation, recovery and iron status. Measured in the Netherlands.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol GGT (Gamma-Glutamyl Transferase) Cortisol DHEA-S Estradiol (E2) Free Testosterone Total Testosterone Folate (Folic Acid) Vitamin B12 Calcium Ferritin Iron (Serum) Magnesium Potassium Progesterone Sodium Transferrin CRP (C-Reactive Protein) Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Total Cholesterol Albumin AST (Aspartate Aminotransferase) Vitamin D (25-OH) Insulin (Fasting) Leukocyte Differential Creatine Kinase (CK) Transferrin Saturation Triglycerides Basic Blood Count

€399,-

Health Checkups

Complete Metabolic Panel

Comprehensive metabolic panel: electrolytes, kidney, liver, glucose, HbA1c, and protein.

Bicarbonate Calcium Chloride Potassium Sodium Glucose (Fasting) HbA1c (Glycated Hemoglobin) Albumin ALP (Alkaline Phosphatase) ALT (Alanine Aminotransferase) AST (Aspartate Aminotransferase) Bilirubin (Total) Urea (BUN) Creatinine eGFR (Estimated Glomerular Filtration Rate) Total Protein

€149,-

Whoop

A 43-biomarker comprehensive health panel inspired by WHOOP Advanced Labs — a deep look at metabolism, cardiovascular risk, hormones, liver, kidney and inflammation.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol Cortisol DHEA-S Estradiol (E2) Free Testosterone FSH (Follicle Stimulating Hormone) LH (Luteinizing Hormone) Total Testosterone Bicarbonate Calcium Chloride Ferritin Iron (Serum) Magnesium Potassium Sodium Transferrin CRP (C-Reactive Protein) Homocysteine Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Total Cholesterol Albumin HOMA-IR ALP (Alkaline Phosphatase) AST (Aspartate Aminotransferase) Bilirubin (Total) Total Protein Urea (BUN) Creatinine Vitamin D (25-OH) eGFR (Estimated Glomerular Filtration Rate) Insulin (Fasting) Leukocyte Differential Transferrin Saturation Lipoprotein(a) Triglycerides Basic Blood Count

€499,-

Whoop

Whoop Heart Health

A 45-biomarker heart health panel inspired by the WHOOP Heart Health Panel — an advanced look at cholesterol, lipoproteins, inflammation and kidney function.

Complete Blood Count (CBC) Leukocyte Differential ALP (Alkaline Phosphatase) ALT (Alanine Aminotransferase) AST (Aspartate Aminotransferase) Albumin Total Protein Bilirubin (Total) ApoB (Apolipoprotein B) Total Cholesterol LDL Cholesterol HDL Cholesterol Triglycerides Lipoprotein(a) Urea (BUN) Creatinine eGFR (Estimated Glomerular Filtration Rate) Calcium Bicarbonate Chloride Sodium Potassium Magnesium Cortisol DHEA-S Estradiol (E2) FSH (Follicle Stimulating Hormone) LH (Luteinizing Hormone) SHBG (Sex Hormone Binding Globulin) Total Testosterone Free Testosterone TSH (Thyroid Stimulating Hormone) Glucose (Fasting) HbA1c (Glycated Hemoglobin) Insulin (Fasting) HOMA-IR CRP (C-Reactive Protein) Homocysteine Ferritin Iron (Serum) Transferrin Transferrin Saturation Vitamin D (25-OH) Cystatin C Uric Acid

€629,-

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A 50-biomarker performance panel inspired by the WHOOP Performance Health Panel — recovery, blood production, thyroid, hormones, iron and nutrient status for people who train.

€689,-

Whoop

Whoop Metabolic Health

A 51-biomarker metabolic panel inspired by the WHOOP Metabolic Health Panel — blood sugar regulation, insulin, thyroid, liver and the mineral cofactors behind your metabolism.

€799,-

Whoop

Whoop Women's Health

A 53-biomarker women's health panel inspired by the WHOOP Women's Health Panel — fertility, cycle and thyroid hormones plus a complete metabolic and nutrient base.

€709,-

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Whoop Men's Health

A 48-biomarker men's health panel inspired by the WHOOP Men's Health Panel — testosterone, PSA and prostate health plus a complete metabolic and hormone base.

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InsideTracker

InsideTracker Recovery

A 10-biomarker recovery panel inspired by InsideTracker's Recovery category — muscle enzymes, liver values, electrolytes, magnesium and vitamin D behind your recovery score.

Magnesium CRP (C-Reactive Protein) ALT (Alanine Aminotransferase) AST (Aspartate Aminotransferase) GGT (Gamma-Glutamyl Transferase) Albumin Creatine Kinase (CK) Sodium Potassium Vitamin D (25-OH)

€139,-

InsideTracker

InsideTracker Metabolism

An 11-biomarker metabolism panel inspired by InsideTracker's Metabolism category — blood sugar, insulin, HOMA-IR, the full lipid profile, ALT and TSH behind your metabolism score.

TSH (Thyroid Stimulating Hormone) Insulin (Fasting) ApoB (Apolipoprotein B) Glucose (Fasting) HbA1c (Glycated Hemoglobin) ALT (Alanine Aminotransferase) HDL Cholesterol LDL Cholesterol Triglycerides Total Cholesterol HOMA-IR

€169,-

Medical standards

Dr. Naimi oversees the medical standards behind our content and assessments.

Medical policy

CIBG Ministerie van Volksgezondheid,
Welzijn en Sport Official BIG registration BIG 49928676701

Doctor's Assessment Included

Every result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.

ALT (Alanine Aminotransferase)

€8,-

Reference Ranges

ALT (Alanine Aminotransferase): what this test measures

ALT (Alanine Aminotransferase): why this value matters

ALT (Alanine Aminotransferase): when is testing worthwhile?

ALT (Alanine Aminotransferase): symptoms of a high or low value

Low Levels

High Levels

ALT (Alanine Aminotransferase): what to do about an abnormal value

Male

Female

ALT (Alanine Aminotransferase): lifestyle and this value

ALT (Alanine Aminotransferase): frequently asked questions

Test Products

InsideTracker

Complete Metabolic Panel

Whoop

Whoop Heart Health

Whoop Performance Health

Whoop Metabolic Health

Whoop Women's Health

Whoop Men's Health

InsideTracker Recovery

InsideTracker Metabolism

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Medical standards