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Here's How Long the Effects of Caffeine Last

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How Long Does Caffeine Last? 

When that first drop of caffeine hits our tired, miserable lips, we're instantly transformed. We become happier, full of energy and know our coffee is going to get us through the day. But how long do these feelings last?  

The answer: Caffeine lasts in our systems anywhere from 4 to 6 hours on average, and it has a half life of about 5 hours. That means if you consume 200 milligrams of caffeine, after 5 hours, you'll still have 100 milligrams left in your body. It only takes about 45 minutes for 99 percent of the caffeine in our morning joe to be absorbed into our bloodstreams.  

A woman pouring a pot of coffee with a gaming setup in the background.

What is caffeine? 

Coming from the leaves and seeds of many plants, caffeine is a nature-made drug. When consumed, it gives you that temporary energy boost, mood lifter and alertness you long for because it stimulates the central nervous system, raises heart rate and blood pressure. Caffeine’s effects hit us in just a few minutes, helping us battle through our day much happier, lighter and without feeling tired—but it’s also addictive. 

Factors that contribute to how long caffeine lasts include: 

1. How much caffeine you're consuming in milligrams

Moderate consumption of caffeine per day is around 200 to 300 milligrams. So if you are riding the over or under on that, then the effects of caffeine will vary from person to person and day to day. If you brew a mug of Death Wish Coffee one day and opt for an espresso or instant the next, you will notice a difference in how caffeine impacts you. Other variables like age, weight and gender also affect how those milligrams of caffeine make us feel. 

2. How dependent you are on caffeine

Caffeine’s popularity—for most people—is due to its immediate and positive effects. It’s an addiction—it keeps us coming back for more. For people who regularly consume caffeine, it’s perfectly normal to find you’ve become somewhat dependent on the caffeine and built up a tolerance, which simply means your body gets used to having caffeine every day. That’s likely why you reach for another mug—or two or three—to keep riding that caffeinated high. For others, brewing one quick cup of your favorite brew is the jumpstart you need to rock the day, so caffeine’s effects won’t linger as long then. 

3. How much water you're drinking

Since our bodies contain a lot of it—as much as 70%, it’s obvious that water is the key to a healthy, happy, hydrated body. Water gives your metabolism a natural boost and helps fuel your brain, too. So if you are properly hydrated before, during and after you have your cups of caffeinated coffee, then you’ll actually improve the caffeine effects and avoid the negatives that you may feel from consuming those cups. It naturally flushes the caffeine from your body and prevents build up from happening. 

4. How sensitive you are to caffeine

Once caffeine enters your body, it triggers the release of dopamine in your brain and puts you in a better mood, which is why it's considered a psychoactive drug. And the reason why caffeine keeps us alert and awake is because it blocks the sleep-inducing molecule adenosine in our brains.  

But coffee affects way more than just our brains—research has found it has an effect on our livers, our hearts and moreThe antioxidants. minerals and other compounds in coffee also help prevent inflammation that leads to arthritis and other chronic diseases, cancers and Type 2 diabetes. It's important to note that caffeine affects each person differently—and it's scientifically known that humans have 3 levels of sensitivity to caffeine. This determines how well you metabolize caffeine and how it affects you in general. Caffeine has a greater effect on people who are sensitive to it. For example, caffeine-sensitive people could experience some annoying symptoms like a headache, racing heartbeat, feeling nervous or fidgety, irritability and even fatigue, to name a few.  For others, you will feel little or no effect at all.  

Genes play an important role, too—those with a specific variation of the gene PDSS2 process caffeine more slowly than others. Therefore, they need less coffee for the same stimulant effects.  

At the end of those 4 to 6 hours, you may feel yourself experiencing the dreaded caffeine crash with symptoms of extreme tiredness, inability to concentrate and irritability. But luckily, there are many ways to prevent this from happening in the first place. And if you’re looking for natural ways to amp up your energy in addition to that caffeine, consider these options: 

RELATED: How Much Caffeine is Too Much Caffeine?