A liver function test is a blood test that measures enzymes and breakdown products from your liver, usually ALT, AST, gamma-GT, bilirubin and alkaline phosphatase. Together they give a sense of how your liver cells and bile ducts are doing. You usually do not need to fast for it.
I advise people not to draw a liver panel right after a heavy weekend or a tough training session. Otherwise you mainly measure the noise, not your baseline.
What is a liver function test?
A liver function test is a panel of blood values that brings your liver into view. It measures not a single value, but a set you read together. That way you see whether liver cells or bile ducts are responding to something.
The name is a little misleading, because the test mainly measures damage and irritation, not your whole liver function. Still, it is a useful, low-threshold check. The full overview of the markers is in the pillar liver values explained.
Which blood values are in a liver panel?
A standard liver panel contains a few fixed markers. This table shows what they measure and what athletes watch for.
| Marker | What it measures | Athlete note |
|---|---|---|
| ALT (ALAT) | Liver cells, fairly liver-specific | Stays high apart from training, then it weighs more |
| AST (ASAT) | Liver cells, muscle and heart | Can rise after hard training |
| Gamma-GT (GGT) | Bile ducts | Sensitive to alcohol and substances |
| Bilirubin | Breakdown of red blood cells | Mildly raised can be harmless |
| ALP (alkaline phosphatase) | Bile ducts and bone | Rises with bone turnover |
Our 360 Health test includes such a liver-function panel, alongside other values. To understand a raised result better, read elevated liver values: causes and symptoms.
How do you get your liver function tested?
For most liver values you do not need to fast. Still, a clean baseline is handy. Leave the alcohol for a few days to a week and avoid a hard training session just before the measurement, especially if you want to read your AST honestly.
Why the latter? AST also comes from muscle, so a hard session can lift the value. We explain that link in high ALT and AST.
With us you draw at a fixed location and get your results digitally, with an assessment by a BIG-registered doctor. That way there is context alongside your values.
When do people choose a liver function test?
This is a choice, not a prescription. Some people choose a liver panel when they train a lot, drink alcohol regularly, use medication or supplements, or simply want to set a baseline. According to Thuisarts.nl, a liver test can deviate due to fatty liver, alcohol and medication among other things.
For anyone pushing their limits with substances or supplements, it can be extra relevant. The Dopingautoriteit lists liver dysfunction as a possible side effect of anabolic substances. More on that in liver values and substances.
How do you read your result?
First look at which value deviates and by how much. A mild, isolated deviation is different from several sharply raised values. Always read your result against the reference values on your own lab sheet.
A raised result is not a diagnosis, but a starting point for the conversation with your GP. They can decide whether further steps are needed. The RIVM raises questions about the safety of some supplements, so bring your use into that conversation.
Frequently asked questions
Do you have to fast for a liver function test? For most liver values, no. A few days without alcohol and without hard training does give a cleaner baseline.
Which values belong to a liver panel? Usually ALT, AST, gamma-GT, bilirubin and alkaline phosphatase, sometimes with albumin added.
Can I test my liver function at home? With us you draw at a fixed location and get your result digitally with an assessment by a doctor. That gives more context than isolated home measurements.
What does a liver function test cost? That depends on the panel you choose. A liver-function panel is part of our broader 360 Health test.
Conclusion
A liver function test is a low-threshold way to see how your liver handles the load of training, alcohol and substances. The trick is in the preparation and in reading the pattern.
My advice: test rested, set a baseline and discuss a raised result with your GP.
References
- Thuisarts.nl. The liver tests in my blood are not good. Accessed 2026.
- Dopingautoriteit. Anabolic substances. Accessed 2026.
- RIVM. Use and safety of doping and sports nutrition supplements. Accessed 2026.
Disclaimer
Every blood test result includes a professional assessment from a BIG-registered doctor. This article gives general information and is not a substitute for medical advice. For treatment decisions, discuss your results with your GP.
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