30/05/2026
Here's something most people don't realise about caffeine - your response to it is largely determined by your genetics.
Caffeine is broken down in the liver by an enzyme called CYP1A2.
Depending on your genes, you might be a fast, intermediate, or slow metaboliser.
And this explains so much about why coffee works beautifully for some people and leaves others feeling anxious and wired.
Fast metabolisers process caffeine quickly. They get that clean energy lift and feel great. These are the people who can have an espresso after dinner and sleep soundly.
Most people fall into the intermediate category. They process caffeine at a normal pace, which means timing matters. A coffee before 11am is usually fine, but anything later can interfere with sleep.
Then there are slow metabolisers. These people can have a single coffee at 8am and still feel jittery by lunchtime. They often struggle with anxiety and poor sleep, even with minimal caffeine intake. For them, largely avoiding caffeine is often the answer.
Here's the good news: we don't have to guess.
Gene testing can tell us exactly how your body handles caffeine - along with insights into how you process nutrients, respond to exercise, and clear toxins.
In clinic, I use a simple cheek swab test that gives us a detailed picture of your unique genetic makeup.
From there, we can personalise your diet, lifestyle, and supplement approach based on what your body actually needs.
Save this for later if you've ever wondered why caffeine affects you differently than everyone else.
