Coffee is great in the morning to kickstart the day. But it’s not so great at night when you’re left wide awake and struggling to sleep.
So how long does caffeine stay in your system? Unfortunately, that’s not a straightforward question.
Caffeine affects us all differently and how long it lasts will depend on your age, metabolism, and how much caffeine you have — just to name a few factors.
Below, we’ll dive into how long caffeine typically lasts and how you can enjoy coffee and sleep.
“Caffeine lasts longer than you think," says Dr. Chester Wu. "It can stay in your system for more than 12 hours, so an afternoon coffee could keep you awake at bedtime or disrupt your sleep during the night. You don’t have to give up coffee altogether, though. Enjoy caffeine in the morning and switch to decaf or caffeine-free drinks around lunchtime.”
Dr. Chester Wu is double board certified in Psychiatry and Sleep Medicine, and provides sleep medicine services, medication management, and psychotherapy to adults at his private sleep medicine and psychiatry practice.
Caffeine can last for more than 12 hours in your system. But the exact amount of time will look different for everyone, and it may even change for you from day to day depending on how much caffeine you consume. How long caffeine lasts in your system and how long the effects — like increased alertness — last can be different, too.
Let’s dive into how long caffeine lasts in more detail.
In general, caffeine lasts in your system for more than 12 hours. But the amount of time caffeine lasts depends on:
A single dose of caffeine has a half-life of three to seven hours. This means it takes three to seven hours for the amount of caffeine in your system to decrease by half.
Let’s say the half-life of caffeine is five hours for you. That would mean if you had 100 milligrams of caffeine at 12 p.m., there would be 50 mg in your system at 5 p.m. and 25 mg by 10 p.m., and so on.
Caffeine’s half-life can be different for everyone and it may be longer if you have more caffeine. This means the time it takes your body to clear half of the caffeine in your system can vary. And don’t be fooled into thinking 50% of the caffeine isn’t much — it can still disrupt your sleep.
Caffeine’s effects may last for more than 12 hours. But this number will be different for everyone depending on how your body reacts to caffeine. And different caffeine effects may last for different amounts of time.
A 2021 meta-analysis found caffeine may improve your:
But it’s not yet clear how long these individual effects can last.
For example, when it comes to memory, caffeine’s effects can be seen after 24 hours. In one study, participants who had 200 mg of caffeine performed better on a memory test 24 hours later compared to those who had a placebo.
When it comes to reaction time, on the other hand, caffeine’s effects may diminish quickly. In one study, consuming a 6 mg/kg dose of caffeine (equivalent to 408 mg for a 150 pound individual) 90 minutes before a visual reaction test did not speed up reaction times as expected. It was theorized that caffeine might have been consumed too early in relation to peak plasma levels (estimated at 60 minutes after supplementation) and thus caffeine’s effects with regards to reaction time would have been limited due to incorrect timing.
How long caffeine can keep you awake will be different for everyone and depend on many factors, like how much caffeine you have, how sleep deprived you are, and your genetics.
A study that administered 200 mg of caffeine 16 hours prior to bedtime found that even with a large time gap and low blood levels of caffeine, caffeine’s impact on sleep was still noticeable.
On the other hand, you may also develop a tolerance to caffeine, meaning some effects from your regular dose won’t last for very long or at all.
How long a cup of coffee lasts depends on how much caffeine is in the coffee and on factors like your age, metabolism, and genetics.
In general, caffeine can stay in your system for more than 12 hours and it has a half-life of three to seven hours.
The caffeine content of a “cup” of coffee can vary widely. Cup sizes can be very different and the amount of caffeine in a particular cup size depends on the coffee beans and how they’re brewed.
One “cup” of instant coffee can contain 30 mg to 90 mg, but a venti 20-ounce cup of coffee from Starbucks can contain about 410 mg of caffeine.
The more caffeine a cup of coffee has, the longer it’ll last in your body.
{{ cta }}
Stop drinking coffee about 12 hours before bed — or even earlier if you find you’re sensitive to it. This should give your body enough time to break down all the caffeine in your system, so it doesn’t keep you up.
That 12-hour mark is just an estimate, though.
Caffeine affects us all differently, so there’s no one agreed-upon caffeine elimination time. Different studies share different recommendations.
And when you need to stop drinking coffee may be different from when you need to stop drinking energy drinks or avoid taking a pre-workout supplement — both of which often can contain more caffeine than a cup of coffee.
Research from 2023 states you should avoid coffee at least nine hours before bed and pre-workout at least 13 hours before bed to avoid reducing your sleep time.
RISE acts as a caffeine calculator and gives you an exact caffeine cutoff time that’s tailored to you each day.
To give you a caffeine cutoff time, RISE predicts the timing of your circadian rhythm, or body clock, based on factors like your inferred light exposure and last night’s sleep times.
As part of your circadian rhythm, you’ll see your Melatonin Window in the RISE app. This is what we call the roughly one-hour window of time when your body’s rate of melatonin is at its highest. Melatonin is your sleep hormone, so your Melatonin Window is the ideal time to head to bed. The timing of your Melatonin Window can shift each day depending on your sleep times.
Each day, RISE sends you a reminder to limit caffeine 10 hours before your Melatonin Window that night. You can adjust the timing of this reminder if you find you’re more or less sensitive to caffeine.
Most people’s cutoff time will be around noon. Night owls may be able to drink caffeine a little later into the day, until around 2 p.m. As with everything to do with caffeine, this will be individual to you and depend on many factors.
There’s no hard-and-fast rule for how late is too late to drink coffee. The time will be different for everyone. But, in general, you want to avoid caffeine about 12 hours before bed.
Caffeine can disrupt your sleep, even if you stop drinking it hours before trying to sleep.
One study gave participants 400 mg of caffeine zero, three, or six hours before bed to compare the differences. The results showed each of these caffeine times disrupted sleep. That included those who had caffeine six hours before bed — their sleep time was reduced by more than one hour compared to those who had taken a placebo.
And caffeine can do more than just keep you awake.
Research from 2023 shows caffeine can reduce your total sleep time, increase how long you’re awake during the night, increase the amount of light sleep you get, and decrease the amount of deep sleep you get.
In general, anything more than 400 milligrams of caffeine a day is too much.
The US Food and Drug Administration (FDA) recommends consuming a maximum of 400 mg of caffeine a day.
If you drink energy drinks, it’s recommended you stick to one can of energy drink per day.
Research suggests 300 mg of caffeine a day isn't linked to adverse health effects in healthy adults. But this may be too much for some people.
If you’re sensitive to caffeine or have a health condition like high blood pressure, you might want to consume less caffeine than this — or none at all.
And if you’re pregnant or breastfeeding, The American College of Obstetricians and Gynecologists, recommends you stick to less than 200 milligrams of caffeine a day. Speak to your healthcare provider to make sure it’s okay for you to consume caffeine and get personalized advice on how much.
Too much caffeine can lead to side effects such as:
If you become dependent on caffeine and don’t have it, you may experience withdrawal symptoms. Caffeine withdrawal symptoms include:
When you consume caffeine is just as important as how much you consume. Sure, 400 mg spread across the morning may be okay. But it’s a different story if you have 400 mg of caffeine in the late afternoon or evening.
In general, avoid caffeine about 12 hours before bed to make sure it doesn’t keep you up or check RISE for your daily caffeine cutoff recommendation.
You can learn more about how much caffeine is too much here.
It can take 15 minutes to two hours for caffeine to fully kick in and reach peak levels in your system, so you may feel the stimulating effects of caffeine fast. Caffeine is completely absorbed by your body in 45 minutes.
How long it takes caffeine to kick in will be different for each person, though.
Here’s how you can stop caffeine from affecting your sleep:
How long caffeine affects your sleep will depend on factors like how much caffeine you have and your genetics.
Caffeine doesn’t just keep you awake, though. A 2023 meta-analysis found caffeine can:
So sticking to that all-important caffeine cutoff time can improve your whole night of sleep, which will improve your energy levels the next day.
Need a caffeine-free pick-me-up? We’ve covered how to get energy without caffeine here.
If you feel like caffeine isn’t working for you, or doesn’t work for long, there are a few reasons that could be to blame:
{{ video }}
Sometimes caffeine can work, but it leaves you feeling more tired than before. That could be due to:
We’ve covered more reasons why caffeine makes you tired here and why caffeine doesn’t affect you here.
To rule out sleep debt, you can use RISE to find out if you’ve got any sleep debt and how much sleep you should be aiming for each night. The app also predicts the timing of your circadian rhythm each day, so you can see when your energy is expected to dip.
Heads-up: You may need more sleep than you think. We looked at how much sleep 1.95 million RISE users aged 24 and up need. It ranged from five hours a night to a whopping 11 hours 30 minutes a night. The median was eight hours.
RISE works out how much sleep you need using a year’s worth of your phone use data and proprietary sleep-science-based models. You’ll know how much sleep to aim for each night, so you don’t need to rely on caffeine for energy.
It’s hard to get caffeine out of your system faster.
If you’ve had too much caffeine and you’re feeling jittery or anxious, you can reduce caffeine’s side effects by:
If you’ve had caffeine too close to bedtime and you’re struggling to sleep, you can try to make yourself tired by:
Remember to make a mental note of how much caffeine you had or how close to bedtime you had it so you don’t make the same mistake twice.
Caffeine works by stopping adenosine (a chemical that makes us feel sleepy) from working in our brains.
Here’s a quick biology lesson.
When you ingest caffeine, enzymes in your liver break it down, metabolizing it into paraxanthine and theophylline. These compounds temporarily block the A1 and A2 adenosine receptors in your brain.
Adenosine is a natural chemical that builds up in your system the longer you’re awake, making you feel sleepy over time. But if adenosine can’t bind to your receptors — because paraxanthine and theophylline are there instead — you won’t feel the sleepiness it causes.
Caffeine doesn’t just block adenosine, though. It stimulates your central nervous system and triggers the release of adrenaline, giving you a mental and physical energy boost. Caffeine makes us feel more alert and increases attention, reaction times, and memory.
Caffeine can be found in coffee, tea, energy drinks, soft drinks, and chocolate.
How much caffeine these foods and drinks contain depends on the type of coffee beans or tea leaves, how they’re made, and the serving size.
Here are the typical caffeine levels in common foods and drinks:
Caffeine can last for more than 12 hours, but this can depend on your age, metabolism, and how much caffeine you have — and that’s just for starters.
RISE can make things simple by giving you an exact time to stop drinking coffee (or any other caffeinated beverage) each day. This time is based on your circadian rhythm and can be tailored if you find you’re more or less sensitive to caffeine.
When you know your caffeine cutoff time, you can enjoy coffee in the morning, cut yourself off when RISE tells you to, and give your body plenty of time to break down the caffeine you’ve had before bedtime.
We found 80% of RISE users get more sleep within five days, so you don’t have to choose between caffeine and a good night’s sleep.
It can take more than 12 hours for coffee to wear off. How long it takes for coffee to wear off depends on factors like your age, metabolism, and how much caffeine you’ve had. The half-life of caffeine is three to seven hours. This is how long it takes half of the caffeine in your system to clear. So caffeine can last for a different amount of time for everyone.
Caffeine may affect your sleep more than 12 hours after you’ve consumed it as it can last in your system for more than 12 hours. Caffeine can keep you awake, wake you up in the night, and reduce the amount of deep sleep you get. Aim to avoid caffeine about 12 hours before bed to stop it from disrupting your sleep.
The half-life of caffeine can be anywhere from three to seven hours. So, if you drink 100 mg of caffeine, you'd still have 50 mg in your system about five hours later, and 25 mg about 10 hours later. It can take more than 12 hours for caffeine to leave your system, so aim to avoid caffeine about 12 hours before bedtime.
The half-life of caffeine can be anywhere from three to seven hours. So, if you drink 200 mg of caffeine, you'd still have 100 mg in your system about five hours later, and 50 mg about 10 hours later. It can take up to 12 hours for caffeine to leave your system, so aim to avoid caffeine about 12 hours before bedtime.
The half-life of caffeine can be anywhere from three to seven hours. So, if you drink 300 mg of caffeine, you'd still have 150 mg in your system about five hours later, and 75 mg about 10 hours later. It can take up to 12 hours for caffeine to leave your system, so aim to avoid caffeine about 12 hours before bedtime.
Caffeine can last for more than 12 hours, but this depends on your age, metabolism, whether you take medication, and how much caffeine you’ve had. RISE is a caffeine calculator that tells you when to stop consuming caffeine each day to stop it from keeping you awake at night.
Learn more about Rise for sales teams.
RISE makes it easy to improve your sleep and daily energy to reach your potential
