Hoe reageer je op cafeïne? sensitiviteit tolerantie A1 A2A koffie
2 min Reading time

How do you react to caffeine?

Florian Fermin
Florian Fermin

People react very differently to coffee and caffeine. Some people can drink 10 cups of coffee without effect and others start jumping and dancing after just one cup. How do you react to caffeine? What causes this? And what makes the effect of caffeine so different per person. This depends on two points, namely tolerance and sensitivity.

In your brain you have adenosine receptors. Normally, adenosine attaches to these receptors and this makes you feel tired. You have two types of these receptors A1 and A2A. One plays an important role on caffeine tolerance and the other on sensitivity.


Have you ever drunk a lot of coffee for weeks in a row? And by a lot I mean more than five cups a day? Once you've done that, you've probably also noticed that after a while you need more to get that energy boost. This is because just like weed and alcohol, you can also build up a tolerance to caffeine. This is due to the A1 adenosine receptors. When you drink more caffeine, these receptors ensure that less caffeine can bind to the adenosine receptors and more of the caffeine is reflected. This means you need more coffee for the same effect. But in addition to this tolerance, caffeine sensitivity also plays a major role in how you react to caffeine and how much you need to get extra energy, for example.


The sensitivity has everything to do with how your liver digests the caffeine. In a normal or rather average person, 95% of the caffeine that comes in is digested and converted into other things that benefit your body, the other 5% goes to your brain. This is where the A2A receptor comes in. Namely, normally the adenosine attaches to these receptors and this ensures that you get tired. But when you drink coffee, caffeine binds to this receptor and this blocks the feeling of fatigue.

But, when you walk around Amsterdam Central you probably already know this, not everyone is normal. Some people have a more active or less active A2A receptor and this determines your sensitivity. This also ensures that some people feel a greater or smaller effect after a cup of coffee, but you can't do anything about this, because that's how you were born.

And now the cool thing, the answer to the question; How do you react to caffeine? therefore depends on two points.

For example, it could be that even more of your caffeine is digested by your liver, leaving less than 5% available to your brain.