Caffeine Overdose Symptoms: Signs, Cases, Prevention


Top 10 Caffeine Overdose Symptoms

Here are the usual symptoms in order from the first ones to be experienced to the more severe, later stage consequences.

  1. Jitters, Restlessness, and Nervousness
  2. Increased heartbeat
  3. Nausea
  4. Anxiety
  5. Heart palpitations (cardiac arrhythmia)
  6. Insomnia
  7. Sweating
  8. Dizziness
  9. Vomiting
  10. Cardiac arrest

There can be many common symptoms that indicate too much caffeine consumption, but these are the most prevalent.

These symptoms should be recognized and further caffeine intake should be stopped to avoid more serious and even life-threatening symptoms.

Ingesting massive doses of caffeine all at once is particularly dangerous as it doesn’t give your body time to react. Overdose symptoms serve as an early warning system.

Caffeine’s major effects are experienced for at least 4 hours.

  • This is longer for those sensitive to caffeine.
  • This is longer with extremely large doses.
  • This is based on the half-life of caffeine which is 4-6 hours.

It’s hard to pinpoint an amount of caffeine that will cause these caffeine overdose symptoms as people have different tolerance levels.

Are You Addicted to Caffeine?

You may want to consider quitting. A detox program like Wean Caffeine is scientifically designed to help you quit caffeine gradually and safely. This prevents the horrible withdrawal most people experience when quitting.

Prevention: Maximum Daily Intake

You can prevent caffeine overdose by adhering to the recommended safe dosage guidelines.

Generally, a dose between 250-500mg (check caffeine amounts here) could produce some of the above mild to moderate symptoms, especially in those with no tolerance of high caffeine sensitivity.

Those with a caffeine allergy or sensitivity could have severe symptoms even after a very small dose.

Click here to find out how much of a popular drink would it take for you to overdose.

DSM-5 Criteria

Insomnia is a common symptom of too much caffeine

Caffeine Intoxication is now included in the DSM-5 physicians manual.

The official diagnosis can be made when any 5 of the following symptoms are present: restlessness, nervousness, excitement, insomnia, flushed face, diuresis (you keep passing urine), gastrointestinal disturbance (upset tummy, diarrhea), muscle twitching, rambling flow of thought and speech, tachycardia or cardiac arrhythmia, periods of inexhaustibility, or psychomotor agitation.

The DSM-5 now also lists Caffeine Withdrawal as a mental disorder. Sufferers can experience withdrawal symptoms when ceasing caffeine intake.

Caffeine Addiction as a disorder was rejected from the next version of the manual.

Reducing the Impact of Caffeine

There is some research indicating products that contain rutaecarpine can actually reduce the impact of caffeine’s side effects. They do this by assisting with caffeine metabolism*. Learn more here.

Caffeine Overdose Documented Cases

Caffeine overdose does happen and has been documented. Here are some of the more recent cases resulting in death or hospitalization;

  • 19-year-old James Stone dies after taking 25 to 30 No Doz pills in 2007. (at least 2.5 grams of caffeine)
  • 40 Seagulls die from caffeine overdose in Canada this year from eating used coffee grinds.
  • 17-year-old Jasmine Willis, a Durham, UK waitress overdosed by drinking 7 double espressos in 2007. She was taken to the hospital but recovered soon after. (that’s roughly 1.078 grams)
  • In the late 1990’s an Australian woman, with a heart condition died after consuming a guarana based shot from her local health food store. This product is no longer on the market. (10g/liter, ok that’s just nuts!)
  • 2010 a 23-year-old British man from Mansfield, England died after taking to 2 spoonfuls of pure caffeine powder washed down by an energy drink at a party. His death was ruled accidental.
  • 2011 Fourteen-year-old Anais Fournier, died after she consumed two 24 ounce Monsters (480mg of caffeine) in a 24 hour period. The cause of death was a heart arrhythmia due to caffeine toxicity.  There seem to be some conflicting stories as to how much she really consumed and this seems true since 480mg in a 24 hour period isn’t a toxic amount. Update October 2012: Her parents are suing Monster Energy for wrongful death although the girl did have a known pre-existing heart condition.
  • 2012 The FDA is investigating Monster Energy since the energy drink has been linked to five deaths over the past year.
  • 2013: According to the Substance Abuse and Mental Health Services Administration, energy drink-related ER visits have doubled in the last 4 years, however, 42% of these visits involved caffeine in combination with other drugs such as alcohol or other narcotics. src.
  • 2013 a New Zealand woman died from cardiac arrhythmia associated with her 10 liter/day Coca-Cola habit. She also smoked 30 cigarettes a day and barely ate. Caffeine was a contributing factor, but the 900-1000mg daily dose wasn’t the only factor. src.
  • 2013 A mother is suing Monster Energy for the death of her 19-year-old son, Alex Morris, after he died of cardiac arrest. She claims that he drank two 16 ounce Monsters the day before his death and at least two a day for the 3 years preceding his death. A California Coroner’s office reported that he died from cardiomyopathy and cardiac arrhythmia.
  • October 2013: John Jackson from the UK dies after eating a whole tin of HERO Energy Mints. Each tin contains 12 mints, so he consumed 984mg of caffeine. He also had cirrhosis of the liver, which prevented him from processing the caffeine properly allowing it to build up in his bloodstream to lethal levels. (src.)
  • March 2014: A 14-year-old boy from Norway was hospitalized with kidney failure after drinking 4 liters of a caffeine-laced energy drink while gaming for 16 hours straight. This would be around 1,280mg of caffeine if he was consuming a “Red Bull” like energy drink. (src.)
  • September 2014: A Tennessee man was taken to the hospital after consuming 20 caffeine pills to “test the limits of his body” according to what the man told the paramedics. He ingested 4000 mg of caffeine at once. src.

Caffeine Overdose Facts

too-much-caffeineLuckily for us, we have mechanisms built into the human body that let us know we’ve had enough of something.

This is true with caffeine overdose. Well before we are at a toxic level we experience side effects that prevent us from consuming more, i.e. nausea and vomiting.

This means that before the 149 or so cans of Red Bull that it would take to kill an average adult male, vomiting would most certainly happen.

For most, that would happen after about can number 5!

It’s important to note, however, that caffeine is a drug and should be respected and not abused. Since some people have extremely low tolerance to caffeine, they could  – in theory – overdose quite easily.

How to Know If You’ve Overdosed

Most people feel the “jitters” first – a sensation of tremors or shaking.

This is your signal to stop consuming caffeine for the day.

You should also be aware of the caffeine levels in what you are drinking. Please consult the caffeine database. Some of the caffeine amounts will surprise you.

If you are finding you are often tired after consuming caffeine this is a sign that you need to change your long-term habits and could indicate adrenal fatigue.

The bottom line is to be aware of what you are consuming.

How common is caffeine overdose?

With the plethora of caffeinated products in the marketplace, one could assume that overdosing on caffeine is quite common.

If we look at the statistics from The American Association of Poison Control Centers we find that, while it does exist, it isn’t as common as we might think.

In fact, overdosing on Tylenol is a lot more common than overdosing on caffeine.

Since caffeine is consumed so widely, there are a lot of half-truths, hearsay, urban legends, media hype, and even fiction.

It’s good to take an honest look at the subject and try to put all of the information into perspective. We can then determine if caffeine should be in the same category as other drug overdoses are.

Get Help Quitting Caffeine

Reduce your caffeine intake without pain and discomfort.

See our new 10-step plan
  • D

    So I like to take a certain workout supplement for extra energy (not caffeine). I buy my supplements in bulk so I happened to have similar looking white bags, one filled with the supplement and one filled with anhydrous caffeine powder. One day I messed up (very stupid) and mistook the bag of caffeine for my regular workout supplement. I ended up measuring out a little over four grams of what I thought was the supplement, mixing it in a large cup of water, and slamming down the concoction. Lucky for me, not all the caffeine dissolved in the water. If caffeine were a less hydrophobic molecule, I probably wouldn’t be typing this today. I estimate that I took somewhere between three and three and a half grams of pure caffeine within 5 minutes.

    Two hours later I shook violently and moaned painfully between sessions of vomiting. I prayed for death but the sweet solace never came as I proceeded to stare bug-eyed and delirious at the ceiling for the next fourteen hours. Sleep was a thing of myth. I wouldn’t wish that feeling on the worst of my enemies. Don’t OD on caffeine.

  • antmanbee

    dead seagulls
    ho ho ho
    very funny:(

  • krazy

    this all sounds like bullcrap

  • Anna

    I think I am experiencing dehydration, nausea and jitteryness as I speak. 4 shots of espresso may have been a bit too much in 1 hour. Especially considering that I never drink energy drinks. I’ve had one full throttle this year, and rarely drink coffee. I’ve been downing water like there’s no tomorrow, but my head feels like it’s drowning. If poor judgment doesn’t kill me, my final exams will.

  • Matt

    I have drinkin about 10 monsters all in the same hour… and i didnt feel any of these side affects you all are talking about, does that mean there is something wrong with me? i drink 4 monsters b4 every basketball game i play and all that happens is i steal the ball more. no extra sweating or anything… ive taken 4 caffeine pillls of 80mg each and washed it down with two monsters and still nothing. i barely got perked up

  • ted

    @Matt, some people can actually have type of natural immunity to caffeine.. You must be one of those rare people… 🙂

  • michelle

    im 29 yrs old and last yr i had a caffiene overdose. i took 4 five hr energy shots right before work cuz i was so tired. i got to work that mornin and i didnt feel right they called my husband to come get me and he did i felt like i was dieing but at that point didnt know what was going on i always took 3 to 4 of the shots a day and had been for almost 2 years. well to make the story short i have no kept caffiene. out of my body and i now have a very high anxiety disorder that effect my life everyday as a wife a mother of 3 and as a boss

  • ted

    So Michelle, basically you ignored the warning on the bottle to consume no more that 2 shots a day?

  • shasne

    You just need to pay attention to how you drink energy drinks. I’ve been drinking two and three energy drink a day. I do not claim to be the healthiest person alive. And im propably going to end up with a kidney stone the size of a grape fruit. BUT, you body will filter the caffeine. It you drink it over a period of time the worse you will get is the gutters or an upset stomach. The overdose cases are were they decide to take 1000mg in one sitting nd your body can process it so it all hits you at once.


    ive had 1000mg of caffeine pills in one swallow and never over dosed. It is not possible to overdose on energy drinks so go wild!

  • billy

    I don’t know where this website is getting its facts from, but a friend of mine passed away in 2005 from a caffeine overdose, yes just caffeine. He worked at starbucks and on his way out he had made two venti size glasses of expresso with only about 15-20 shots each and drank both on his drive home… when he got upstairs to his room his heart ruptured and he died right there on the floor…. he had no prior heart problems and did not use other drugs. Yes you die from caffeine… and its not as rare as this website makes it seem… eat a bottle of nodoz… you will die… not to mention the 1000’s of people allergic to caffeine who could die with a dose of as little as 150mgs… or the thosands of people with neocartiagenic problems and other heart murmors or diseases…

  • ted

    Sorry to hear about your friend, but it’s still not very common. We analyzed the national poison control centers data here. It shows that a lot more people overdose on Tylenol than caffeine. We aren’t saying it doesn’t happen but we need to keep things in perspective and not let the sensationalism of the media distort the facts.. Your friend consumed up to 40 shots in a matter of minutes that’s 3200mg of caffeine that’s way beyond what would be considered safe.

  • Mandy

    Don’t listen to anyone that says you can’t overdose on caffeine. And it doesn’t take as much as you think to cause severe effects. I had about 6 or 7 pops a day for two days and ended up having to go to the ER from tachycardia and extreme trembling. It took 2 saline bags to get me up to somewhat normal hydration levels. And I was drinking water and juice along with the pops so it’s not from being stupid. It’s not bullcrap and it’s not funny to go through that.

  • Joe

    Over the course of an hour and a half, when I worked at a coffee, shop I downed aprox. 26 shots of espresso on a whim/bet. I didn’t die. I just had extreme cold sweats along with some vomiting. It was all cool within like an hour or so.
    Some people just can’t handle their caffeine and to them I say GET STRONGER!

  • Matt is full of crap. Having watched him play this explains why he is soo bad. Caffeine has ruined his brain

  • Jess

    I’ve experienced two caffeine overdoses, and am recovering from one now as i type this. The first time was the worst experience of my life. I don’t weigh very much, and i’d drank a bottle of mountain dew and 2 doctor peppers. Late that night, i broke out into a cold sweat, and my heart started to pound very fast and hard. My muscles jerked and twitched, my mouth went dry, and my stomach felt awful. The effects subsided a little later the next morning, but i still felt very shaky and my heart still fluttered. I hadn’t slept in 16 hours, so that night i was exhausted, and even though i wasn’t completely over it, i was able to sleep, even if it wasn’t very sound. When i got over it, i swore to myself i’d be much more careful. This second time, i don’t know what happened; i only had a few sips of coca-cola, and i’m having the same symptoms-only not as severe. I guess i just have a low tolerance for caffeine, so i’ll have to cut it out of my diet completely now. I couldn’t stand going throught this again!

  • ted

    Hi Jess- It sounds like you may have a caffeine allergy

  • Jessica

    7 months I had a crazy experience from caffeine overdose. In less than 3 days I had drinked 14 and a half of energy drinks. I had some Rockstar 2x drinks, which has 250mg of caffeine in them, I also had some Rockstar Pink which has 120mg, and some Rockstar Recovery which has 80mg caffeine. I had some of the symptoms that were listed and I also had numbness in my entire body.At the I was taken to the hospital, and that’s basically my story.

  • Dan

    I’m 17 years old and don’t drink caffeine at all. The only caffeine I consume is in GU energy gels and that is a small amount. I can’t stand the taste of energy drinks and I think I am blessed to have this because I can go walking around school and it seems like everyone has a rockstar or monster and when they’re in class they’re either super tired STILL or super hyper… I don’t see the need for energy drinks or large amounts of caffeine if we all eat correctly but we are America….

  • Tyler

    That’s good Dan, I’m one of those people that always has a Rockstar with me. I didn’t start caffeine until a few months ago and now I literally cannot go a day without it. They don’t even really help anymore. My tolerance has made drinking an energy drink with 200 mg of caffeine and 60+ grams of sugar feel like what a candy bar would do, practically nothing, but if I don’t drink one I get terribly lethargic and down. So yeah don’t ever drink them they’re terrible for you, I’m starting to feel a little discomfort in my heart from time to time and will probably die of some cardiac problem.

Last Modified: November 13, 2017


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