How Long Does Caffeine Stay In Your Body?

Think about what time you usually drink your first cup of coffee in the morning. Are you the type who programs the coffee maker the night before, so you wake up to that delicious smell? Or maybe you wait until after you power through your morning workout or get to your place of employment. Whenever you choose to take that first sip, do you ever wonder how long it will take for the caffeine buzz to kick in, or how long it will last? Probably not. Most of us simply enjoy the taste of the coffee. The energy boost is just a welcome side effect. Well, how your body metabolizes caffeine is fascinating. And in the interest of maintaining good sleep hygiene, it’s worth your while to learn a bit about it. 

How Does Caffeine Get into Your System?

There are many ways that caffeine enters your system. You can take a pill, of course, and some foods contain it. There’s even caffeine-infused gum you can chew. But most of us get our caffeine through beverages. Coffee, tea, espresso, lattes, soda, and energy drinks all contain various amounts. Believe it or not, the human body is extraordinarily efficient when it comes to metabolizing caffeine. Because most people consume caffeine in beverages, your gastrointestinal tract can quickly and efficiently disperse it into body water. Studies show that when we eat or drink something that contains caffeine, 99% of it is absorbed by the body within 45 minutes. That’s an incredibly high rate of absorption. So, what happens when the caffeine arrives?

What Does Caffeine Do to the Body?

Caffeine is a stimulant that primarily affects the Central Nervous System. It is the most popular CNS stimulant used across the globe. Once you ingest a caffeinated beverage, it quickly passes through your digestive tract into body water, where it is transported throughout your entire system. Most people begin to feel the effects of caffeine on the body within five minutes, and it reaches its peak anywhere between fifteen minutes and two hours. You’ll feel more awake, have an easier time focusing, and feel like you have more energy than usual. Athletic performance may improve, and you may react more quickly to stimuli. The biological reason behind this is relatively simple. 

Adenosine is a molecule created within the body. As part of the digestion process, glucose breaks down into glycolysis, which is then further broken down into adenosine-triphosphate (also known as ATP). ATP is responsible for the transmission of energy between cells. ATP is not infinite; it gets used up as it goes about its job. When that happens, it turns into plain adenosine. In the brain, adenosine attaches itself to specific receptors, causing blood vessels to dilate and nerve cell activity to slow down. This process is what causes a person to feel drowsy. 

Caffeine is an adenosine blocker. To our cells, caffeine and adenosine look very similar. When caffeine comes knocking on the adenosine receptor’s door, the receptor readily agrees to let it in. However, unlike adenosine, caffeine does not slow things down. It causes neurons in the brain to fire like crazy, making the pituitary gland sit up and take notice. The pituitary gland now thinks something important is going on that we need to pay attention to, so it releases a flood of hormones that triggers the production of adrenaline in the body. We all know what adrenaline can do – it’s what allows people to lift cars all by themselves to save lives in dire situations. While you may not need to lift a car every day, that little adrenaline kick certainly helps you finish that project your boss needs to be done by mid-morning. 

Half-Life of Caffeine

Now you know the biological reason caffeine gives you that jumpstart when you need it. But what we’re here to answer is the all-important question, how long will it last? When discussing how any drug is detectable in the human body, people usually refer to its ‘half-life.’ The half-life of a drug is considered the length of time required to decrease to half of its starting dose in the body ( As we discuss how long caffeine’s effects last in the body, it’s essential to examine its half-life. Take a look at the following chart:

In an average healthy adult, caffeine has a half-life of approximately five hours. A typical ten-ounce cup of coffee contains about 100mg of caffeine. For the sake of this exercise, let’s assume you drink that cup of coffee at 7 a.m. As you can see from the chart above, you will still have 50mg of caffeine in your body by lunchtime. At 5 p.m., that one little cup of coffee still leaves 25mg of caffeine in your system, and by 10 p.m., you’re finally down to 12.5mg. 

All in all, it takes a little over 24 hours for the average person to metabolize and expel the caffeine from one small cup of coffee from your body. However, this can change based on the individual. Those that are more sensitive or of advanced age could see these times double. 

Notice that those figures are based on a single ten-ounce cup of coffee. Most mugs hold anywhere from twelve to sixteen ounces, and coffee shops tend to offer much larger sizes. Not to mention the second cup you have at 10 a.m., plus the can of soda at lunch, and the chocolate bar you have in the early afternoon. You can see how it adds up!

What does Caffeine’s Half-Life Mean to You?

Based on what you now understand about how long caffeine stays with you, other thoughts and questions are probably presenting themselves. We imagine they sound something like this:

  • How come I feel jittery on some days and not others? 
  • Why can I drink eight cups of coffee a day and still be tired?
  • I drink an energy drink every morning, and I’m still dragging by lunch.
  • I only have 8 ounces of coffee in the morning, but I can't sleep at night.

Unfortunately, there is no easy answer. Many, many things affect not only how long caffeine remains in your system, but how you respond to the drug itself. Lifestyle factors can play a role, such as how much exercise you get, how much water you drink, and how much food you’ve eaten. Certain biological factors also matter. Your age and weight can undoubtedly make a difference. In fact, it could depend on your DNA!

A recent study shows a correlation between a person’s caffeine sensitivity and a gene known as PDSS2. Depending on the makeup of gene PDSS2, a person can experience three levels of caffeine sensitivity: Hypersensitive, Normal Sensitive, and Hyposensitive. Hypersensitive people take much longer to metabolize caffeine. They can feel extreme symptoms when ingesting a minimal amount. Hyposensitive people can consume large quantities of caffeine and hardly feel a thing. Those in the normal sensitive group fall somewhere in the middle. It may explain why you can drink ten cups of coffee between dinner and bedtime and sleep like a baby while your spouse drinks a small cup and doesn’t sleep for days. 

Do You Build Up a Tolerance to Caffeine?

How much of a buzz you get from a dose of caffeine depends mainly on how much you consume regularly. There is no doubt that when you ingest caffeine for the first time, or after a period of abstention, you will experience the effects more acutely. You’ll feel extremely alert and very motivated. You might even be in an excellent mood, possibly to the point of euphoria. As you repeat this day after day, those side effects will flatten out some. And this is a good thing because most people genuinely enjoy the taste of coffee and other caffeine-laden beverages. Tolerance allows you to experience these small joys of life without much consequence. Notice how we said much.

Caffeine and Sleep

People have a love/hate relationship with sleep. As human beings, we obviously need to sleep, and most of us love to sleep. But sleeping takes time. And because we are also busy human beings, putting off going to sleep is how we add more time to our day. How do most of us accomplish this? By using caffeine. Did you stay up late to finish a project? Maybe you were awake all night comforting your frightened child, or the dog kept you up. Or, perhaps you have too much on your mind. Whatever the reason, when you’re alarm goes off the next morning, your first thought may be:

“I’ll need an extra cup of coffee today.”

And this is fine if it only happens occasionally. But relying on caffeine over and over can have harmful effects on your sleep/wake cycle. Wouldn’t it be great if there was a way to drink all the coffee you wanted (or needed!) and still get a good night’s sleep? 

Daily De-Caffeinate and Rutaecarpine

That’s a question we were determined to answer. We at Do Good For Your Body sought to find something that would allow us to drink all the coffee we desired without sacrificing a restful night’s sleep. That’s how we came by an active ingredient called Rutaecarpine. Derived from the Evodia fruit, which is native to China and Korea, Rutaecarpine has been used in traditional Chinese medicine since the 1st Century AD. We used this extract of the Evodia fruit to create a natural acting supplement called Daily De-Caffeinate. This sleep aid works with your body’s natural ability to rid itself of excess caffeine. Now you can enjoy that afternoon or evening cup of joe without worrying. Take Daily De-Caffeinate two hours before bedtime, and you’ll be ready for a peaceful slumber. 


Caffeine is a stimulant that works on the Central Nervous System. When imbibed through various beverages such as coffee, tea, and soft drinks, it produces a state of increased wakefulness, focus, motivation, and elevated mood. Caffeine also has a relatively long half-life, with a single cup of coffee taking over 24 hours to wash entirely out of the body. Because of this, sometimes ingesting too much caffeine during the day can interfere with your body’s ability to fall asleep at night. Daily De-Caffeinate works with your body’s natural ability to rid itself of caffeine. The active ingredient comes from the Evodia fruit, a staple of traditional Chinese medicine for centuries. Daily De-Caffeinate makes it possible to drink your favorite caffeinated beverage late in the day and still get a good night’s sleep. You can read more about Daily De-Caffeinate here.

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A bottle of Daily De-Caffeinate, a solution for reducing caffeine's effects and promoting restful sleep.A bottle of Daily De-Caffeinate, a solution for reducing caffeine's effects and promoting restful sleep.
Do Good For Your Body Daily De-Caffeinate
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