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Coffee & Health

Does Coffee Wake You Up?

To many people, morning is simply not complete without a cup of their favorite cup of brew. Sip after sip, they begin to feel more alert, happy, focused, and energetic, regardless of the quality of the night’s sleep.

But most have never stopped to wonder how coffee does this or if the brew really wakes them up.

In this article, we’ll delve into answering the question of whether coffee really wakes you up or why it may not be getting you expected results.

woman drinking her morning coffee to wake her up.

How Much Caffeine in Your Coffee?

While caffeine content varies greatly depending on the type and brew, an average cup of coffee (8 oz) contains approximately 95 mg of coffee. Caffeine is the bitter chemical contained in coffee that is responsible for the effects you feel after consuming coffee. It’s the central nervous system stimulant that many rely on to get through the day with a jolt of energy. For this to happen, caffeine affects the brain and the central nervous system by increasing the adrenaline and fight-or-flight response, part of the reason for your energized body.

How Caffeine Wakes You Up

In the body, caffeine disguises itself as an adenosine receptor. Adenosine is the neurotransmitter that relaxes the brain causing the feeling of tiredness, sleepiness, and drowsiness. Naturally, the brain continually makes the sleep-inducing receptor while you’re awake, which is why the longer you’re awake, the more adenosine your system will have. More adenosine in the body signals to the brain to slow down. The chemical works by slowing down nerve firing; as a result, the body becomes tired as brain activity slows down and you start to feel relaxed.

When consumed, caffeine intercepts this process; it prevents adenosine from attaching to the receptor, and instead, it binds up the molecules preventing the receptor from activating. It blocks any effects of adenosine, which leads to reduced tiredness and sleep, and doubles alertness.

Further, caffeine also increases the brain activity of neurotransmitters–dopamine and norepinephrine—and adrenaline levels in the blood. The release of these hormones communicates flight which may be the reason for a faster heartbeat, dilated pupils, and energized muscles. The combination causes the brain further stimulation, which promotes arousal, focus, and alertness. For these reasons, caffeine is considered a psychoactive drug.

Most people will feel the jolt of energy in the first 15 to 60 minutes of drinking coffee when its effects reach peak levels in the blood. How long the caffeine will last in your body varies based on several factors such as genetics, tolerance, and physical health. Most often, the effects will last five to six hours, but some of the caffeine will remain in the body longer.

Why Your Coffee Doesn’t Wake You Up

Even though understanding how coffee works is fairly straightforward, the reasons why it doesn’t work for you may not be that clear. Several reasons explain why the preferred wake-up brew will not work for you. Even though there are no defined answers to that, here are the main reasons why it may not be working:


The rate at which human body metabolism occurs differs hugely from person to person. Generic components come to play here where the adenosine receptors that coffee targets vary based on genes. Besides, the main liver enzymes that metabolize coffee differ hugely. If metabolism occurs naturally for you, you will feel the effects of caffeine more than others; other people will not feel it at all.

Lifestyle and Coffee Intake

Ideally, everyone shapes their caffeine sensitivity with their coffee-drinking habits. The more coffee you drink, the more you develop tolerance to coffee, meaning you’ll need more to feel its effects. If you’ve been drinking 5 to six cups of coffee every day and all of the sudden it stops working, you’ve probably become tolerant, and it may be best to consider cutting back.

In addition, the frequency of coffee intake determines the level of stimulation in the system. Typically, the half-life of caffeine is approximately five to six hours after intake, which means that by that time, half of it is still in the system.

If you drink two 8-ounce cups of coffee (about 200 mg of caffeine) at 11 pm, about 100mg will still be in your system when you awake. Taking another cup of coffee at this point will not have the same waking effect as someone who has had none of it in their system. For the same reasons, if you don’t want caffeine to keep you up at night, avoid coffee in the afternoon. The caffeine may disrupt your sleep for up to six hours of drinking coffee.

Medical Factors

Certain medications also affect the metabolism of coffee in the body. This is because the liver enzyme (cytochrome P450) metabolizes other drugs besides caffeine. If the liver enzymes are occupied processing another drug while you’re drinking your hot cup of black coffee, the caffeine will take more time to be processed. The caffeine will wait for its turn to be metabolized, which may explain why it’ll not hit right away. Some other medications will reduce the metabolization of coffee while others will reduce their effects which may explain why coffee may not be working for you.

Changes in Coffee Roast or Brew

It’s also possible that various coffee types and brews will affect your body differently. Different roast qualities will vary in their composition and caffeine levels, so if you find your coffee betraying you all of a sudden after a change in variety, it’s definitely the coffee. Similarly, if you’ve switched from a lighter to a dark roast, you’ll not get the same levels of effects. A lighter roast will have higher caffeine levels to wake you up in the morning.

While the brewing method will not affect how caffeine works, it’ll affect the caffeine levels. Though rare, this may explain why your coffee isn’t strong as normally would.

Exhaustion Levels Too High

If you’re too tired or struggling with insomnia, caffeine will not help feel more alert; instead, it can even heighten effects like anxiety and jittery feeling without actually waking you. Try finding out the reason for your sleep quality before pouring that extra cup of coffee.


Dehydration is a chronic concern, and coffee doesn’t make it any better. As a diuretic, coffee can dehydrate you even more, if taken in high doses. Although it rarely happens, extreme dehydration from the consumption of coffee will exhaust you rather than wake you up. It can cause you to feel tired and drowsy even after drinking the strong cup of your brew. Some extreme levels of dehydration will cause you headaches, among other health concerns. To combat these adverse effects and experience full stimulation from coffee, ensure you drink plenty of water before and after each cup of coffee.

Caffeine affects people differently. To most, coffee wakes them up–almost instantly–while to others it’s a totally different story. You might know someone who can pound several cups of strong black coffee and appear impervious to its effects while someone else gets jittery within a few sits of a light cup of coffee. If you want that wakening morning effect from your brew, you now know what to consider and the best time for your caffeine kick if you want to feel alert throughout your morning.


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