Exactly How Long Does Coffee Keep You Awake?

The Best Answer:

The answer to this question differs according to the individual. You have to take into account factors such as caffeine content, volume consumed per day, total sleep time per day or week, and of course your overall health and metabolism.

For many people, a cup of coffee in the morning is the perfect way to start the day. No wonder, after all, a freshly brewed coffee tastes delicious and is also a practical stimulant. In the afternoon, too, many connoisseurs like to drink a coffee to overcome the lunchtime low or as a complement to cakes and biscuits. 

However, many people reject coffee in the evening, because everyone knows the warning that you cannot sleep well after a coffee. Some coffee drinkers have already had the experience that they were downright sleepless after drinking coffee and lay awake for a long time. 

Does Caffeine Keep You Awake?

Does Caffeine Keep You Awake

For many of us, coffee is almost a magic drink that lets us approach everyday life in an alert and attentive manner: We drink it in the morning to shake off the tiredness of the night, at noon to concentrate on going to the meeting, and in the afternoon before the performance slump sets in.

But on some days, no coffee in the world seems to be able to shake off the sluggish feeling inside you. Why is that? Well, it’s because of caffeine.

Caffeine is part of the coffee bean. Depending on the type of coffee bean, the coffee contains more or less caffeine. The two most popular coffee beans Arabica and Robusta, for example, differ significantly in their caffeine content. 

While the arabica bean with a caffeine content of 1.1 to 1.7% is considered to be heart-friendly, the robusta is a real pick-me-up. Here the caffeine content is 2 to 4.5%. Extracted caffeine is a white powder that tastes bitter but is completely odorless. The caffeine content, along with numerous other aromas, contributes to the typical taste of coffee.

Caffeine has a noticeable effect on the body. We ourselves usually notice it from a faster heart rate and increased blood pressure. The blood vessels in the body expand, but in the brain, they narrow. The central nervous system and the entire metabolism are also stimulated by the stimulant caffeine. 

As a result, we are more alert, more active, and more focused. Since every person has an individual caffeine tolerance, an overdose can quickly occur. Then the body reacts with a headache or nervousness and the positive effects turn into negative ones.

The rumor still lingers that strong, bitter coffee has higher caffeine content than a mild drink. However, this is not the case as the method of preparation does not affect the caffeine content. 

Only the caffeine contained in the coffee powder influences the stimulant factor of the coffee. Since different coffee specialties are prepared with different amounts of powder, this is the reason for the different caffeine content.

Nevertheless, there are always people who can sleep well even after a coffee and do not feel any effects. So why is it that coffee has such different effects? And is the myth that coffee makes you sleepless in the evening really true?

Important facts:

  • The caffeine content varies depending on the coffee bean. For example, a robusta bean contains significantly more caffeine than an arabica bean.
  • The effect of the caffeine sets in after half an hour, because then the caffeine has reached the bloodstream. However, it takes the body about five hours to break down half of the caffeine again.
  • Caffeine ensures that the natural need for sleep is shifted backwards and can thus permanently disrupt the natural rhythm.

How Long Does Coffee Keep You Awake?

Coffee’s effect only sets in after half an hour, because then the caffeine has reached the bloodstream. It takes about five hours for the body to break down half of the caffeine again. No wonder, then, that coffee consumed late has an impact on the quality of sleep. 

In fact, the stimulant even affects the body’s biorhythm. The natural need for sleep is shifted backward and can thus permanently disrupt the natural rhythm. If you want to prevent this effect, you should stop drinking coffee five hours before the desired time to fall asleep – or drink decaffeinated coffee.

By the way, there are people who can sleep perfectly even after consuming coffee. Why these people do not react or react only slightly to caffeine has not yet been researched. So try the effects of caffeine on your body. 

Breaking down the caffeine

Caffeine has a half-life of around 5 hours. Someone who consumes 40 milligrams (mg) of caffeine has 20 mg left in their system after 5 hours.  The level of caffeine in the blood peaks around 15-45 minutes after consumption. The caffeine is then quickly broken down by the liver.

Most people notice the greatest effects during this time, and many reports feeling nervous, urinating, and having sudden bursts of energy. These symptoms tend to go away as the caffeine breaks down.

Why Coffee Sometimes Makes You Tired Instead of Awake

Why Coffee Sometimes Makes You Tired Instead of Awake

The caffeine contained in coffee makes us more productive, whether at work, in everyday life, or during sports. It is not for nothing that caffeine was on the list of banned substances of the World Anti-Doping Agency (WADA) until 2004. However, this effect only works if the coffee drinker sleeps enough.

In a 2016 study, researchers at the Walter Reed Army Institute of Research found that even three nights with less than five hours of sleep negate the performance-enhancing effects of coffee. So when your coffee doesn’t kick anymore, leave it out and get some extra sleep instead.

It’s also possible that you naturally have too much adenosine in your body. Adenosine is considered to be the antagonist of caffeine: the body produces the substance when it is exerted so that people do not overuse it. 

Adenosine promotes sleep, it attaches itself to receptors and signals rest to the nervous system. At the same time, the blood pressure is lowered. Caffeine works in exactly the opposite direction and separates itself from the receptors that are normally intended for adenosine.

In order to compensate for this misconception, the body produces more and more receptors with regular and high caffeine consumption, to which adenosine can still dock – and the caffeine already loses its stimulating effect because there is too much adenosine in the body.

Frequently Asked Questions


How late is too late for coffee?

Every day, we depend on our bodies to function. It’s no wonder that a cup of coffee wakes us up in the morning and keeps us going throughout the day. We need to fuel our bodies with food and drinks like coffee for them to stay healthy and be able to perform at their best.

But when does it become too late for coffee? The answer is that the answer is different for everyone depending on a number of factors including age, health condition, and even gender. So, my advice is to observe how your body and metabolism react to caffeine and adjust your coffee drinking habits according to that.

How long after coffee can I sleep?

Many people struggle with their sleeping habits and can’t go to bed before they feel the need to drink caffeine. The answer to this question is different for everyone, but the general consensus is that you should be able to go to bed at least 4 hours after you drink your coffee.

Everyone has a different tolerance for how long it takes them to sleep, but the general rule of thumb is that you should be able to go back and forth between sleep and wakefulness without difficulty.

Does coffee actually keep you awake?

Caffeine is a well-known chemical that stimulates the nervous system. When it gets into the body, caffeine increases heart rate and blood pressure, which increases energy levels and improves mood.

Caffeine works quickly and many people feel the effects within minutes. The effect lasts until the body has completely broken down the agent. This duration depends on several factors.

Each person will experience the effects differently, and some may last longer than others. So, yes drinking coffee might keep you awake depending on your own physicality, health, and metabolism.

Can a person build tolerance to caffeine?

As the body becomes resistant to the active ingredient, people who regularly consume caffeine may hardly notice its effects. However, in a person who is very sensitive to caffeine, the effects can last for hours or until the next day.

Final Thoughts

If your coffee is making you tired instead of awake, please don’t start drinking more of it. In general, it is believed that a daily dose of 200 to 400 milligrams of caffeine is not harmful – that’s the equivalent of two to four cups of coffee. The first symptoms of intoxication can occur from 1000 milligrams. 

These include hearing, visual and cardiac arrhythmias, palpitations, and cramps. Instead of increasing the daily dose, it is better not to drink coffee for a few days. Your body and overall health will thank you for it!

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