Your liver processes just about everything you swallow or inject. Some oral substances, prohormones and high-dose supplements can raise your liver values, sometimes sharply. This article explains which blood values may change and why medical guidance matters. It is not an encouragement to use such substances.
I am honest about this: the safest thing for your liver is not to use these substances. If you do choose to, measuring and getting guidance is the least you can do.
Why do oral substances load your liver?
Your liver breaks down substances foreign to the body, and oral substances in particular pass through it in concentrated form. Certain oral, chemically modified anabolic substances are known to load the liver extra. The Dopingautoriteit explicitly lists liver dysfunction as a possible side effect of anabolic substances.
That does not mean every substance or supplement damages your liver. It does mean the chance of raised liver values is higher, and that you do not feel it. Without measuring, it stays invisible.
The basics of how to read those values are in the pillar liver values explained.
Which blood values can change?
Not only your liver enzymes respond. With the use of anabolic substances, several values can shift. This table gives a rough overview. It is information, not a diagnosis or treatment advice.
| Value | What can happen | What it is about |
|---|---|---|
| ALT and AST | Can rise | Irritation of liver cells |
| Gamma-GT | Can rise | Bile ducts and outside load |
| Bilirubin | Can rise | Processing in the liver |
| Hematocrit | Can rise | Thicker blood, see separate explainer |
| HDL cholesterol | Can drop | Unfavourable lipid profile |
The rise in hematocrit, meaning thicker blood, is a known point of attention. What that means and when it becomes a problem is in high hematocrit. For the bile-duct marker itself, read high gamma-GT.
And supplements and pre-workouts?
Even without doping, your liver can get irritated. High-dose supplements, unknown herbal extracts and stacks of pre-workouts can affect liver values. The RIVM points out that the safety of some sports nutrition supplements is not always well established.
According to Thuisarts.nl, medication and other substances can make liver tests deviate. So be honest about everything you use when you have your values assessed.
Why medical guidance matters
If you consciously push your limits, medical guidance is not a luxury but sensible. A doctor can place your values in context and think along about risks. We cannot and will not advise on the use itself, and certainly not on doses or schedules.
In the Netherlands you can turn to your GP and to an anabolenpoli, a clinic for people who use or have used anabolic substances. The Dopingautoriteit also gives independent information about the risks.
Some people choose to have their blood values checked periodically. Whether and how often that makes sense, you decide together with a doctor, not based on a blog.
What can you do yourself?
The safest thing for your liver is not to use these substances. If you are unsure about stopping or tapering, do that in consultation with a doctor. Stopping abruptly can also have effects with some substances, so get guidance.
If you want to bring your liver values into view, you can with the 360 Health test, which includes a liver-function panel. How such a test works is in liver function testing.
And always discuss a raised result with your GP. A blood test is a starting point for that conversation, not a replacement for it.
Frequently asked questions
Do anabolic substances always raise your liver values? Not always, and not equally strongly in everyone. The chance is higher, especially with certain oral substances. Because you do not feel it, measuring is the only way to see it.
Do my liver values drop again after stopping? With a temporary trigger, values often drop, but that varies per person. Get guidance on this from a doctor.
Can I safely use substances as long as I measure? Measuring does not lower the risk, it only makes it visible. The safest is not to use. If you do, get medical guidance.
Where can I go with questions? To your GP, to an anabolenpoli and to the Dopingautoriteit for independent information about the risks.
Conclusion
Oral substances and heavy supplements can shift your liver values and more, without you feeling it. Measuring makes it visible, but it does not remove the risk.
My advice: the safest is not to use. If you do anyway, get guidance from your GP or an anabolenpoli and discuss your values with a doctor.
References
- Dopingautoriteit. Anabolic substances. Accessed 2026.
- RIVM. Use and safety of doping and sports nutrition supplements. Accessed 2026.
- Thuisarts.nl. The liver tests in my blood are not good. Accessed 2026.
Disclaimer
Every blood test result includes a professional assessment from a BIG-registered doctor. This article gives general information and is not an encouragement to use doping or other substances. It is not a substitute for medical advice. For treatment decisions, discuss your results with your GP.
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