How does your body break down drugs and alcohol?

Your liver and kidneys do most of the work of breaking down drugs and alcohol. The liver converts substances using enzymes, mainly the CYP system. The kidneys remove the leftover products through your urine.

How fast this happens depends mostly on a substance's half-life. You can't meaningfully speed it up. You can really only wait.

How does your body process drugs and alcohol?

Your body treats drugs and alcohol as foreign substances. The liver breaks them down step by step with enzymes, including the CYP system. The kidneys filter your blood and pass the leftovers out through urine. A small part leaves through your breath, sweat and stool.

Breakdown usually happens in two phases. In the first phase, enzymes make the substance more reactive. In the second, the body attaches a water-soluble part to it.

This is how a fat-soluble substance slowly becomes a form the kidneys can remove.

The liver is the main organ for this conversion. Enzymes cut a substance into smaller parts that dissolve better in water. The kidneys can then excrete those parts.

Alcohol works through two enzymes. First it becomes acetaldehyde, then acetic acid. The body breaks that acid down further into water and carbon dioxide.

Not every substance follows the same route. Some leave the body almost unchanged through urine. Others turn into breakdown products first, which can stay detectable longer.

What is a half-life?

A half-life is the time it takes for the amount of a substance in your blood to drop by half. If a substance has a half-life of four hours, about half is left after four hours. After another four hours, that's a quarter.

This measure helps estimate how long a substance stays detectable. The longer the half-life, the slower the decline. Many drugs have a half-life of a few hours, though it varies by substance and person.

Alcohol is an exception. Your body processes alcohol at a fairly steady rate, not through a fixed half-life. Roughly, an adult body handles about one standard drink per hour, though this can vary.

A half-life says something about speed, not about whether a substance is still detectable.

The half-life is linked to the detection window. A substance with a long half-life usually stays measurable longer. Still, the test method also decides how long something shows up.

Breakdown products can have their own, longer half-life. That's why a test sometimes stays positive long after you feel nothing.

Want to know more about detectability over time? Read how long drugs stay detectable.

What determines how fast a substance clears?

Speed depends on the substance itself and on your body. Good liver and kidney function helps with smoother breakdown. Age, hydration, genetics and other medicines may influence the pace. So clearance runs faster in one person than in another.

The Farmacotherapeutisch Kompas describes for each medicine how it's broken down and excreted. That information shows how large the differences between substances can be.

The table gives only a general picture. The real pace can differ per person.

Hydration mainly matters for substances that leave through urine. Drinking enough helps the kidneys do their job. It doesn't speed up breakdown in the liver, though.

Genetic differences in enzymes also play a role. Some people have enzymes that work faster, others slower. That partly explains why the same dose acts differently in two people.

Many people think sweating or losing weight helps. Read why that disappoints in our article on exercise, sweating and drug clearance.

Can you speed up the breakdown?

Not really. Your liver works at its own pace, which you can barely steer. Drinking water, coffee, exercise or a sauna don't measurably speed up the liver's enzymes. The only reliable help is giving time so the body can process the substance calmly.

Detox drinks and kits often promise a quick cleanse. The evidence for that is weak. Most products at best dilute your urine briefly, without truly speeding up breakdown.

Time stays the only factor you can really count on.

You can read more in do detox drinks and kits work? and in our explainer on what detox does and doesn't do.

RIVM and Thuisarts.nl give reliable information about alcohol and substances in the body. Want to check your own status calmly? With the extended 10-panel you can check several substances at once, with a professional assessment included.

Sources

• RIVM, information on alcohol and drugs in the body.
• Thuisarts.nl, guidance on alcohol and health.
• Farmacotherapeutisch Kompas, breakdown and excretion of medicines.

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