Caffeine vs. Theine: Effects of coffee and tea

Coffee or tea? We’ll take a detailed look at this dilemma in this article. Coffee and tea are among the most popular beverages around the world. Both, however, contain caffeine—or, in the case of tea, theine. What is the difference between them and what are their effects?

Caffeine and Theine: Differences

Let’s get straight to the point: from a chemical perspective, caffeine and theine are no different. They are in fact the same molecule. The term “theine” is used to refer to the caffeine found in tea, in order to distinguish its origin. Although the substance itself is the same, its effect differs depending on other compounds present in the beverage.

Coffee & Effects

Coffee is known for its fast onset of effects. In addition to caffeine, it contains fewer tannins, which would otherwise slow down its absorption. After drinking a cup of coffee, the caffeine enters the bloodstream and brain quickly, where it blocks adenosine receptors. What is that? It’s a substance in the body that induces the feeling of tiredness. The result is a feeling of energy, alertness, and improved concentration.

Typical effects of coffee in brief:

• quick stimulation (within 15–30 minutes)

• short-term increase in attention

• increased heart rate and blood pressure

• possible feeling of restlessness or “nervousness” with higher doses

Tea & Effects

We already know that tea also contains caffeine, but not only is it called theine, its effects are different. Tea’s effects are milder and more prolonged over time. This is mainly due to the presence of tannins and the amino acid L-theanine. As mentioned with coffee, tannins slow down caffeine absorption, and L-theanine promotes a feeling of calm and relaxation without being sedative. Thanks to this combination, tea tends to offer focused stimulation without a sudden “kick” or subsequent energy crash.

Typical effects of tea in brief:

• gradual and long-lasting stimulation

• supports focus without restlessness

• mood harmonization thanks to L-theanine

• lower risk of nervousness or irritability

How much caffeine do coffee and tea contain?

The amount of caffeine also depends on the type and preparation. But if we were to generalize, it’s true that:

• A cup of coffee contains approximately 80 to 1200 mg of caffeine
• Black tea contains approximately 40 to 70 mg of caffeine
• Green tea contains approximately 20 to 45 mg of caffeine

So coffee is “stronger”, but not everyone benefits from its fast onset and potential side effects. On the other hand, tea, despite its lower caffeine content, may be ideal for those who want to boost concentration and stay calm.

Coffee or tea?

Let’s conclude by answering our main dilemma: What to choose? The choice between coffee and tea depends on what kind of stimulation you need. So let’s sum it up again:

• Coffee: Quick start to the day, energy boost and help with sleepiness
• Tea: Longer focus, gentle stimulation without energy “crash”

Both drinks have their place, and for many people they’re not just a source of energy, but also a part of daily habit.

What’s good to know?

Caffeine has its benefits, but you know how it goes: “too much of anything is bad.” There’s even the term caffeine withdrawal, since caffeine can cause withdrawal symptoms. People who regularly drink coffee, energy drinks or tea and suddenly stop consuming caffeine may experience unpleasant symptoms.

Most common symptoms of caffeine withdrawal:

• Headache – the most typical and frequent symptom

• Fatigue and drowsiness – the body misses the stimulating effect of caffeine

• Irritability, bad mood

• Decreased ability to concentrate and slow thinking

• Muscle stiffness or pain (especially in the neck and back area)

• Nausea or mild stomach discomfort (less commonly)

When and why does it happen?

Caffeine works by blocking adenosine, a substance in the brain that induces fatigue. When we consume it regularly, the body gets used to its effects. After sudden withdrawal, the natural level of adenosine increases rapidly, which can lead to feelings of drowsiness and other mentioned symptoms. These symptoms usually appear 12–24 hours after withdrawal and can last for 2 to 7 days, rarely even longer.

How to avoid it?

The smartest approach is to stick to the recommended daily intake of caffeine. Withdrawal symptoms usually occur only with regular daily intake exceeding 100–200 mg of caffeine.

If you plan to stop consuming caffeine, it’s best to gradually reduce the dose instead of quitting suddenly. Ideally, replace strong coffee with a milder tea. And of course, the golden classics: drink plenty of water and get quality sleep.

Tip: Instead of coffee, try making a Matcha Latte, which also contains L-theanine, antioxidants, and is overall a gentler and healthier version of coffee.

How much caffeine per day is “safe”?

According to experts (e.g., EFSA – European Food Safety Authority):

• An adult can consume up to 400 mg of caffeine per day without negative effects.
• To avoid withdrawal symptoms, even a smaller amount around 100 mg daily is enough if you are used to caffeine.
• With sudden withdrawal after regular intake over 200 mg daily, withdrawal symptoms may occur.