When does coffee wear off?

If you are anything like 63% of the U.S. population, you probably need a good cup of joe to get your day going.

Yet you also might be wondering how this coffee is actually affecting you, and more specifically, how long the effects really last. Now you might be curious because you're taking some new medicine, or maybe you're just a curious type of person who has to know random useless facts.

Either way that's what this article is for and hopefully by the end you have a clear understanding of the effects of coffee and how long they last.


When we talk about how long the effects of coffee last we are usually referring to caffeine. While coffee does have a few other things in it, like sugar if you add it, caffeine is the big one.

The quick answer is that caffeine has a half-life of between 3-5 hours or 4-6 hours depending on your source of info. Which makes sense because if you work a 9 to 5 job you'll often feel a bit of a drag come around at about 2 o'clock. That's sitting right at the beginning marker of when caffeine is going to start to wear off.

It is important to remember that some medications can either increase or decrease the longevity of caffeine. So if you take anything like this please consult your doctor. There are also people with caffeine sensitivities who can feel the effects for several days if it's bad enough. So if you notice that caffeine definitely doesn't just last half your day, be a little careful.

When does coffee kick in?

lady drinking coffee in the morning

If you're trying to figure out how long the effects of coffee are going to last then it would be really helpful to know when it starts to work in the first place.

Basically, about 45 minutes after you start drinking it's basically all the way absorbed into your system. But really it starts getting into your body as soon as you start drinking it. There's a bit of sciency stuff to explain the reason why but to keep it simple when you take the first sip it starts to be absorbed through every place the coffee touches on the way down.

This is another place where your genetics and medications can affect how the caffeine works in your system. Some medications can increase the onset or make it take longer. And some people are predisposed to have it affect them faster due to their biological makeup.

My Brain?!

Yep, your brain. The reason we even drink coffee in the first place, unless you just like the taste, is to keep us awake and give us a boost. That obviously means your brain is going to have to get the caffeine somehow right?

So there's this molecule in your brain called adenosine that is responsible for controlling when you should be sleeping and when you should be awake. Caffeine basically takes up adenosine's place in the brain, making the receptors think they're full and that it's time to be awake. This is what makes it feel like we're not as sleepy after we start drinking our morning coffee.

When caffeine blocks those molecules it also stimulates a tiny bit of adrenaline to be released. This also can have an effect on how energetic you feel because adrenaline is responsible for increasing heart rate and other things associated with being fully alert.

What else does coffee have in it?

coffee beans in a cup


Well, caffeine is the big one but coffee also has things like antioxidants in it.

An antioxidant is a compound that fights something called a free radical. Without getting too far down the scientific rabbit hole free radicals are bad. They come from radiation and smoke inhalation. These pests can cause damage to your cells which can lead to heart disease and even some cancers.

There are a few things that affect the antioxidant levels in coffee, like the kind of roast it is or what you add into it yourself, so don't just start guzzling java to make your heart healthy. Obviously drink it in moderation just like anything else, but if it makes it easier to justify your morning happy-juice then by all means.


So this one is not so good. Diterpenes are one of the things responsible for raising your cholesterol levels. If you're a pretty young person than worrying about cholesterol is probably not something you do very often, but it gets to be more of an issue the older we get.

This substance is mostly present in unfiltered coffee and the way it is brewed has a big effect on how much of this stuff is going to be in there.

Currently, there is research being funded by the US government to use Diterpenes as a medicinal compound. It's still pretty new stuff so it might take some time but we may start seeing even more benefits from the coffee bean.

How can I get coffee out of my system?

The age-old adage of drinking a bunch of water to flush your system doesn't really apply to coffee. This will not remove the coffee from your system any faster, but coffee is diuretic. This means that it can cause you to be dehydrated. So if you drink more water it can make it easier to deal with the effects of coffee.

Eating certain vegetables like broccoli and cauliflower helps to speed up your body's metabolism. This makes the process of getting coffee, and most other things, out of your system a little bit faster.

Getting some exercise is a great way to get your body to burn through that coffee. Not only does it speed up your metabolism and make you burn some more fuel, but it can also help to deal with a lot of the jitters associated with coffee that most people will want to get rid of anyway. Plus it's a great way to burn the energy if you have just a touch too much of it.