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How Much Caffeine Is Too Much? Stay Under 400 mg Daily

In general, you should limit your daily caffeine intake to 400 mg a day. But this may be too much for you if you consume it too close to bedtime.
Written by
Jeff Kahn, M.S., Rise Science Co-Founder
Reviewed by
Chester Wu, MD, Rise Science Medical Reviewer
Our Editorial Standards
We bring sleep research out of the lab and into your life. Every post begins with peer-reviewed studies — not third-party sources — to make sure we only share advice that can be defended to a room full of sleep scientists. Learn more.
Updated Regularly
We regularly update our articles to explain the latest research and shifts in scientific consensus in a simple and actionable way.
Published
2022-11-28
Updated
14 MINS
Woman with cup of coffee thinking about how much caffeine to take

Caffeine is the most widely consumed psychoactive drug in the world, and there are a lot of reasons to love it. It can help shake off sleep inertia — that groggy feeling you get after waking up — it can boost mental and physical performance, it contains plenty of antioxidants, and it has health benefits like protecting you from type 2 diabetes, cancer, and Alzheimer’s disease. There’s even a reported association between coffee consumption and lowered risk of suicide

But, you can have too much of a good thing when it comes to caffeine. Consuming too much can give you unpleasant side effects like jitters and headaches, and it can easily keep you awake at night, which can lead to low energy levels, poor productivity, and all the adverse health effects that come with sleep deprivation. 

How much caffeine is too much exactly? Below, we’ll dive into what science has to say on the matter. We’ll also show you how you can use the RISE app to make sure caffeine doesn’t impact your sleep, as well as ways you can boost your energy without reaching for a cup of coffee. 

How Much Caffeine is Too Much?

There is no one amount of caffeine that’s agreed upon as too much. 

According to the Food and Drug Administration (FDA), you should limit your caffeine intake to 400 milligrams per day. Other research states 300 mg of caffeine is not associated with adverse effects in healthy adults. 

But the amount of caffeine that produces adverse effects depends on:

  • Gender
  • Age
  • Body weight
  • How sensitive you are to caffeine 

The amount of caffeine in foods and drinks also varies widely. It depends on factors like the type of coffee beans or tea leaves, for example. 

As a rough guide, here’s the caffeine content of common foods and drinks:

  • Brewed coffee — about 95 milligrams of caffeine per 8-ounce cup of coffee 
  • A single shot of espresso — about 63 mg 
  • One cup of instant coffee — 30 mg to 90 mg 
  • Decaf coffee — 3 mg to 12 mg (depending on the decaffeination method)  
  • Soft drinks like Coke — 21 mg per 7.5-ounce can  
  • Black tea — 47 mg to 90 mg per 8-ounce cup of tea
  • Green tea — 20 mg to 45 mg per 8-ounce cup of tea 
  • Energy drinks — 50 mg to 160 mg  
  • Milk chocolate — 9 mg per 1.55 ounces 
  • Dark chocolate — 12 mg per ounce 

When it comes to energy drinks, however, more research needs to be done into the long-term effects. For now, it’s recommended you limit yourself to one can per day

Even though 400 mg is generally agreed upon as the caffeine limit, your personal limit may be less than this if: 

  • You’re sensitive to caffeine. 
  • You consume it late in the day — 400 mg of caffeine in the morning might not affect your sleep, whereas 400 mg of caffeine in the hours leading up to bedtime will.
  • You rely on it to get you through the day and you’re starting to consume more and more to get the same effects. 
  • You have health conditions like high blood pressure or take certain medications.
  • You’re pregnant, breastfeeding, or trying to get pregnant. 
  • You’re a teenager or child. 

How Much Caffeine is Too Much When Pregnant or Breastfeeding?

Before consuming caffeine when pregnant, check with your healthcare provider to find out if it’s safe for you and how much exactly you can consume. 

In general, the American College of Obstetricians and Gynecologists says pregnant women should limit caffeine to less than 200 milligrams a day. This is also the limit for those breastfeeding. 

Other research says pregnant women and those planning on becoming pregnant should limit themselves to 300 mg a day. 

If that’s less than you usually consume, you can find out how to get energy when pregnant here.  

How Much Caffeine is Too Much for Teenagers?

While you don’t meet many teenagers who love double-shot espressos, caffeinated drinks like sugary energy drinks, soft drinks, and sweetened coffee drinks are popular in this age group.

According to the American Academy of Child & Adolescent Psychiatry, teenagers should limit themselves to 100 mg of caffeine per day and avoid energy drinks altogether.

Excessive caffeine intake in teenagers can lead to: 

  • Nervousness
  • Irritability
  • Sleep problems  
  • Nausea
  • Cardiovascular symptoms 
  • Osteoporosis 
  • Gastric ulcers 

It’s recommended children under 12 don’t consume caffeine at all. 

What Are the Side Effects of Too Much Caffeine?

The adverse effects of caffeine are different for everyone, but you might be consuming too much of it for you if you notice these negative effects: 

  • Anxiety or nervousness
  • Sleep problems, like not being able to fall asleep  
  • Jitters
  • Dizziness
  • Headaches
  • Upset stomach  
  • Fast heart rate 
  • Frequent urination 
  • Dependency, or needing more caffeine to get the same energy-boosting results 

Can You Overdose on Caffeine?

Caffeine overdose is rare, but it can happen. In large amounts, caffeine can cause a high heart rate, arrhythmias (irregular heartbeats), vomiting, convulsions, coma, and death. Typically, you’d need to consume more than 5 grams of caffeine to overdose, however.

Most of us won’t get close to consuming that amount while drinking coffee and tea, but you should watch out for products with concentrated caffeine such as caffeine supplements and weight loss supplements.

How to Cut Down on Caffeine?

Just found out you drink over the recommended daily caffeine limit? Here’s how to cut down. 

1. Reduce Your Caffeine Intake Slowly 

If you’ve been consuming caffeine for a while, chances are, you’re going to experience some withdrawal symptoms when you cut down. To reduce how badly this affects you, cut down slowly, rather than going cold turkey or suddenly halving your daily intake. 

The American Migraine Foundation recommends reducing caffeine intake by 25% each week to avoid withdrawal symptoms. 

2. Stay Hydrated 

Being dehydrated can cause headaches and fatigue — two things you might be feeling from your lack of coffee to begin with. Lessen these symptoms by drinking enough water each day. 

3. Ride the Wave and Wait it Out 

Withdrawal symptoms won’t last forever. In general, they’ll last between two to nine days and they’ll be at their worst 20 to 51 hours after you’ve had your last sip of coffee. 

The more caffeine you’re used to having, the more symptoms you’ll experience and the more severe these symptoms will be, however. 

You can find out more about how long caffeine withdrawal lasts here, as well as other ways to manage them. 

How to Stop Caffeine Impacting Your Sleep?

You could argue that any amount of caffeine is too much if it’s impacting your sleep. But, you don’t need to give it up altogether if that’s the case for you. Here’s how to enjoy coffee and sleep easy each night.

1. Find Out Your Caffeine Cutoff Time 

RISE app screenshot telling you when to limit caffeine intake
The RISE app can tell you when to stop consuming caffeine each day.

Caffeine can last in your system for more than 12 hours. So, even if you only consume 400 mg or less, if you’re having it too late in the day, you may still have trouble falling asleep.

Stop this from happening by finding out your caffeine cutoff time. This is the time of day you need to stop consuming caffeine to give your body enough time to break it all down by bedtime. 

The RISE app can give you an exact time based on your circadian rhythm, or body clock, each day. Enjoy caffeinated beverages up until this time, then switch to caffeine-free drinks like herbal teas in the afternoon and evening. 

You can learn more about when you should stop drinking coffee here. 

RISE users on iOS 1.202 and above can click here to set up their limit caffeine reminder.

2. Limit Your Caffeine 

Watch out for hidden caffeine after your caffeine cutoff time and when working out how much caffeine you have a day. Beyond the obvious lattes and espressos, you’ll find caffeine in things like chocolate, kola nuts, black and green tea, and even decaffeinated coffee. 

It’s easy to think you’re consuming less caffeine than you actually are. Research shows self-reported caffeine intake is often below actual levels. 

3. Improve Your Sleep Hygiene 

Beyond caffeine, other things can keep you up at night. To stop this from happening, focus on your sleep hygiene, the set of daily behaviors that help you fall asleep faster and wake up less often during the night.

Avoid late-night bright light, exercise, large meals, and alcohol. You may find cutting down on caffeine helps in part, but one of these four things still keeps you awake or wakes you up during the night. 

The RISE app can tell you when to avoid each one. Plus, the app can guide you through 20+ sleep hygiene habits to make sure nothing else gets in the way of a good night’s sleep. 

RISE users on iOS 1.202 and above can click here to set up their 20+ in-app habit notifications. 

We’ve covered more common sleep and caffeine questions here.

How to Get Energy Without Caffeine?

You don’t need to rely on coffee consumption to get you through the day. Here’s how to boost your energy levels, without going over the recommended daily caffeine limit. 

1. Lower Your Sleep Debt

RISE app screenshot showing how much sleep debt you have
The RISE app can work out how much sleep debt you have.

Sleep debt is the running total of how much sleep you owe your body measured against your sleep need, the genetically determined amount of sleep you need each night. 

The RISE app can work out your individual sleep need and how much sleep debt you’re carrying. We measure it over your last 14 nights. 

When your sleep debt is high, you’ll inevitably feel low on energy throughout the day, making it harder to resist drinking more and more coffee. 

We recommend keeping sleep debt below five hours to maximize your energy levels. If your sleep debt is high, you can pay it down by: 

  • Taking naps: Check RISE for the best time to take a nap to stop it from keeping you up at night.
  • Going to bed a little earlier. 
  • Sleeping in a little later: Keep this to one or two hours to avoid disrupting your circadian rhythm.
  • Improving your sleep hygiene: Focus on your sleep hygiene to get more sleep overall at night. You can learn more about sleep efficiency and sleep hygiene here.

RISE users on iOS 1.202 and above can click here to view their sleep need.

RISE users on iOS 1.202 and above can click here to view their sleep debt.

2. Live in Sync with Your Circadian Rhythm 

Your circadian rhythm is your internal biological clock that runs on a roughly 24-hour cycle. It dictates things like your sleep-wake cycle and when your body produces certain hormones. 

When you’re not living in sync with it, you’ll feel low on energy, have trouble sleeping, and you’ll be increasing your risk of everything from heart disease to obesity

You can live in sync with your circadian rhythm by: 

  • Keeping a consistent sleep schedule: Research shows a consistent sleep schedule can boost alertness, even if you get the same amount of sleep on an inconsistent schedule. Aim to go to sleep and wake up at the same times each day, even on weekends. 
  • Eating meals at roughly the same times and not too close to bedtime: Meals can change the timing of your circadian rhythm and keep you up at night. 
  • Go to sleep at the right time for you: Check RISE for your Melatonin Window, the roughly one-hour window of time when your body’s rate of melatonin production will be at its highest. Melatonin helps prime your body for sleep, so heading to bed during this window will help you fall asleep and stay asleep. 

RISE can predict the timing of your circadian rhythm each day, so you can schedule your sleep, wake, and meal times to match. 

RISE users on iOS 1.202 and above can click here to see their circadian rhythm on the Energy screen.

3. Get a Short-Term Energy Boost

RISE app screenshot showing you the best time to get an energy boost
The RISE app can tell you the best time to do energy-boosting activities.

While low sleep debt and living in sync with your circadian rhythm are the best ways to boost your energy long term, there are things you can do for a quick pick-me-up that don’t involve a cup of coffee. 

Try: 

  • Getting some exercise: Even low-intensity exercise has been shown to reduce fatigue, so if you don’t have time to hit the gym, go for a brisk walk around the block. Just be sure not to work out too close to bedtime or it could keep you up. Check RISE for the best time to work out.
  • Drinking a glass of water: Mild dehydration can cause tiredness and just the simple act of drinking can make you feel more alert.  
  • Take a cold shower: Cold water increases your heart rate, blood pressure, and metabolism for an energizing boost. Working from the office and feeling fatigued? Try splashing your face with cold water instead. 

We covered more ways to wake yourself up here. Connect RISE to your calendar and the app can tell you the best time for an energy boost like taking a nap or getting some exercise.

RISE users on iOS 1.202 and above can click here to connect their calendar.

Avoid the Trap of Consuming Too Much Caffeine 

Caffeine can be beneficial for your health and well-being, but more does not equal better. 

When you’re feeling tired, it’s all too easy to grab another cup of coffee. But, consuming too much caffeine, or having it too late in the day, can keep you up at night. This leads to more tiredness the next day, and — you guessed it — more coffee the next day, too. 

While 400 mg is the usual recommended daily limit for caffeine, you shouldn’t be relying on it to get you through the day, but you don’t need to cut it out altogether.

To stop caffeine from impacting your sleep, check the RISE app for your individual caffeine cutoff time each day and limit your caffeine intake after this. 

The app can also help you boost your energy levels without turning to coffee. RISE will work out and keep track of your sleep debt and predict circadian rhythm each day, so you can sync up with it. This way, you can maximize your energy levels, all without worrying about how much caffeine you’re consuming each day.

Summary FAQs

Is 1000 mg of caffeine too much in one day?

Yes, 1000 mg of caffeine is too much in one day. The general recommendation is to limit yourself to 400 mg of caffeine per day. 1000 mg of caffeine in a day can lead to side effects like anxiety, jitters, headaches, and trouble falling asleep.

Is 600 mg of caffeine too much in one day?

Yes, 600 mg of caffeine is too much in one day. The general recommendation is to limit yourself to 400 mg of caffeine per day. 600 mg of caffeine in a day can lead to side effects like anxiety, jitters, headaches, and trouble falling asleep.

Is 500 mg of caffeine too much?

Yes, 500 mg of caffeine is too much in one day. The general recommendation is to limit yourself to 400 mg of caffeine per day. 500 mg of caffeine in a day can lead to side effects like anxiety, jitters, headaches, and trouble falling asleep.

How much caffeine is too much to take at once?

It’s generally recommended to keep daily caffeine consumption to 400 mg a day. If you’re sensitive to caffeine or consume it late in the day, you may need to limit yourself to even less. Use the RISE app to find your caffeine cutoff time to make sure caffeine doesn’t get in the way of you falling asleep at night.

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