What happens if you overdose?

The prominent side effects (erratic heartrate, anxiety, restlessness) of caffeine are noticeable from drinking coffee long before death becomes a serious concern as long as reasonable amounts of coffee are consumed. These side effects can nevertheless be serious.

The exact number of cups will vary depending on what coffee is brewed (and how much ground coffee is used) and consumed. An average cup may have 100-200 mg of caffeine, and due to temperature and volume of water, will require an extended drinking period before accumulating enough to cause serious side effects.

These effects can be exasperated by drinking coffees grown at higher elevations, which allows the coffee more time to develop chlorogenic acids and caffeine. Countries that naturally have high elevations such as Ethiopia and Guatemala may contain higher caffeine levels than others, but these are hard to predict and vary by region as well as varietal. Espresso blends and others containing robusta coffee beans should be well respected, as robusta coffees contain roughly twice the caffeine as Arabica on average.

From Desk Reference to the Diagnostic Criteria from DSM-3-R (American Psychiatric Association, 1987):

Caffeine-Induced Organic Mental Disorder 305.90 Caffeine Intoxication

    1. Recent consumption of caffeine, usually in excess of 250 mg.
    2. At least five of the following signs:
      1. restlessness
      2. nervousness
      3. excitement
      4. insomnia
      5. flushed face
      6. diuresis
      7. gastrointestinal disturbance
      8. muscle twitching
      9. rambling flow of thought and speech
      10. tachycardia or cardiac arrhythmia
      11. periods of inexhaustibility
      12. psychomotor agitation


    3. Not due to any physical or other mental disorder, such as an Anxiety Disorder.

Basically, overdosing on caffeine will probably be very very unpleasant but not kill or deliver permanent damage. However, People do die from it.

Toxic dose

The LD_50 of caffeine (that is the lethal dosage reported to kill 50% of the population) is estimated at 10 grams for oral administration. As it is usually the case, lethal dosage varies from individual to individual according to weight. Ingestion of 150mg/kg of caffeine seems to be the LD_50 for all people. That is, people weighting 50 kilos have an LD_50 of approx. 7.5 grams, people weighting 80 kilos have an LD_50 of about 12 grams.
In cups of coffee the LD_50 varies from 50 to 200 cups of coffee or about 50 vivarins (200mg each).

One exceptional case documents survival after ingesting 24 grams. The minimum lethal dose ever reported was 3.2 grams intravenously, this does not represent the oral MLD (minimum lethal dose).

In small children ingestion of 35 mg/kg can lead to moderate toxicity. The amount of caffeine in an average cup of coffee is 50 – 200 mg. Infants metabolize caffeine very slowly.


  • Acute caffeine poisoning gives early symptoms of anorexia, tremor, and restlessness. Followed by nausea, vomiting, tachycardia, and confusion. Serious intoxication may cause delirium, seizures, supraventricular and ventricular tachyarrhythmias, hypokalemia, and hyperglycemia.
  • Chronic high-dose caffeine intake can lead to nervousness, irritability, anxiety, tremulousness, muscle twitching, insomnia, palpitations and hyperreflexia. For blood testing, cross-reaction with theophylline assays will detect toxic amounts. (Method IA) Blood concentration of 1-10 mg/L is normal in coffee drinkers, while 80 mg/L has been associated with death.


  • Emergency Measures
    • Maintain the airway and assist ventilation. (See Appendix A)
    • Treat seizures & hypotension if they occur.
    • Hypokalemia usually goes away by itself.
    • Monitor Vital Signs.
  • Specific drugs & antidotes. Beta blockers effectively reverse cardiotoxic effects mediated by excessive beta-adrenergic stimulation. Treat hypotension or tachyarrhythmias with intravenous propanolol, .01 – .02 mg/kg. , or esmolol, .05 mg/kg , carefully titrated with low doses. Esmolol is preferred because of its short half life and low cardioselectivity.
  • Decontamination
    • Induce vomiting or perform gastric lavage.
    • Administer activated charcoal and cathartic.
    • Gut emptying is probably not needed if 1 2 are performed promptly.

Appendix A

Performing airway assistance.

  1. If no neck injury is suspected, place in the “Sniffing” position by tilting the head back and extending the front of the neck.
  2. Apply the “Jaw Thrust” to move the tongue out of the way without flexing the neck: Place thumb fingers from both hands under the back of the jaw and thrust the jaw forward so that the chin sticks out. This should also hurt the patient, allowing you to judge depth of coma. 🙂
  3. Tilt the head to the side to allow vomit and snot to drain out.

From conversations on alt.drugs.caffeine:

The toxic dose is going to vary from person to person, depending primarily on built-up tolerance. A couple people report swallowing 10 to 13 vivarin and ending up in the hospital with their stomaches pumped, while a few say they’ve taken that many and barely stayed awake.

A symptom lacking in the clinical manual but reported by at least two people on the net is a loss of motor ability: inability to move, speak, or even blink. The experience is consistently described as very unpleasant and not fun at all, even by those very familiar with caffeine nausea and headaches.

257 thoughts on “What happens if you overdose?”

  1. 800mg of caffeine

    I just took 4 pills of an omega3 supplement, little did i know that it contained 200mg of caffeine and 250mg of green tea extract. So I basically ingested 800mg of caffeine and 1gram of green tea extract. I feel extreme amounts of anxiety. I don’t know if I should go to the hospital or not. Would this amount of caffeine be dangerous in one single dose?

  2. Caffeine and Training

    I remember being warned years ago about the supposed dangers of coffee.  It seems science is disproving what I was told.  Multiple studies have established the health benefits of everyone’s favorite morning pick-me-up.  As this post mentions, it seems to reduce ones risk for diabetes.  But I’ve seen other studies stating that coffee drinkers make have lower rates of cancer (several different kinds) and has other health benefits.  And an article in the New York Times clearly stated that normal levels of consumption do NOT increase a person’s chances of having health problems (no increase in blood pressure or heart problems).  Even the issues of dehydration have been overstated, as stated in the article.

    There are other benefits to drinking coffee.  Taking caffeine before your workout has benefits.  This stimulant will improve your energy levels and focus, meaning you’ll train with more intensity.  It also tends to delay or reduce the onset of pain.  If all this wasn’t enough, caffeine also decreases appetite and helps the body burn fat.  All these benefits come from a drug we’ve been using for centuries. 

    Many of the over-the-counter energy supplements and drink have caffeine as their active ingredient.  Why buy these overpriced formulas when you can get the exact same benefits from something you can make in your own kitchen?  It’s fairly simple: just drink a cup of coffee before you go to the gym.  You’ll probably notice and increase in focus and end up having a better workout.  If you don’t like coffee you could just use caffeine gum or tablets, both of which are relatively inexpensive. 

    1. Proof?

      I would like to see medical proof that drinking coffee before working out is beneficial.  Until then I would NOT recommend it.


      1. Google it, coffee is madd good for you as long as you don’t add a bunch of sugar to it. And if your to lazy to Google it, listen to the multiple podcasts about the benefits of coffee.

  3. How long are the effects felt after a panic attack?

    I’m not a big caffeine person, only really consumed choclate and enjoyed the very odd coffe or tea. About a month ago I was sitting with a friend and I consumed about 5 cups of tea and totally lost it, and thought I was going to die. The effects of this first incident lasted about 5 days and then I thought I was coming back to reality. But then while eating dinner I swallowed a carrot that sort of got caught in my throat and that spawned a massive panic attack which at the time I didn’t know what it was as I thought I was seriously going to die. The effects of that one lasted until I had another one about 3 days later which really came out of nowhere, nothing triggered it. Since then I have had some mild ones but nothing too dramatic. But the problem with me at the moment is I don’t feel 100%, and have moments of unreality and a feeling that there is something not functioning properly within my brain. After the second panic attack I have ceased any caffiene and have been eating very well. I find it hard to concentrate for too long without that feeling creaping up on me which feels sometimes like my vital force is out of sync. Don’t get me wrong, I can perform all my tasks but have this feel of I’m not really there. Please if there is anyone out there who could give me some knowledge on what I am going through that would be appreciated. I don’t usually ask for help, but its been over a month now.

    1. effects

      It can take a while it just depends all on the person .Everyone is diffrent my withdraw symptoms are slowly getting better . Around the 1st of this month Im pretty much caffine free except my 1 cup of coffie in the morning and thats it . When you have a panic attack it uses up all of your energy and you feel drained . You need to get plenty of rest which is easier said than done if you work alot. If you consume more caffine then you are used to it puts your body in to shock . The more caffine you in take gets the body going faster I realized . Caffine affects alot in your body your mind, cardiac , your sex drive, your appetite , how much peacefull rest you get. 

      1. Still here

        Thank you for your reply my friend. Well its been 10 weeks and I still have this thing in my mind that just sits there, and disempowers me from preforming all that I would like to do. I haven’t had a panic attack since my first message, or haven’t touched any caffeine, but this thing in my mind is still there waiting for another attack to come. Is this normal for anyone out there who suffers from panic attacks? My diet has always been healthy and remains that way, I’m really not sure what to do, I just want to go back to normal. Personally I’ve had enough, so if there is anyone out there who can help me get over this, then I’m all ears.

        1. Don’t despair just yet

          Hi, it sounds to me as if you are experiencing dissociation which is basically when you don’t feel like your mind is conected to your body, you may have visual or auditory hallucinations, you may struggle to tell the difference between reality and unreality and everything starts to feel unreal and sort of… distant from you. It’s a natural response to extreme stress either that’s happened in the past or is happening in the present. It can be absolutely terrifying but I promise you that you are not going mad and it can be stopped. If you can, tell the person that you feel most comfortable telling and see if it relieves some worry. If not, don’t panic! Try out a psychologist, they’re not as bad as you think 🙂

          I hope you feel better soon.

        2. Jason,
          I went through the


          I went through the EXACT same thing. Just like you, I wasn’t much of a coffee drinker. But I started drinking it regularly over a few weeks and I ended up feeling like that EXACTLY. I felt disconnected from everything, like I wasn’t really there and couldn’t get excited about anything (not even seeing my favourite band live, or taking a trip with my friends). I also panicked a lot and experienced may of the above symptoms in this article. But guess what, I managed to find a cure!!!

          I went to a homeopath and got soemthing called Nux Vomica, which was meant to get rif of the caffeine. You could also try somethign called “coffeea cruda”. Basically, the Nux Vomica gets the caffeine out and the coffeea cruda produces effects that are the opposite of coffee (it makes you calmer). This stuff seriously saved my life! Let me know how you go 🙂 

    2. How to Handle Panic Attacks

      So first let’s validate what you are feeling.  It is real, and for some can resemble a stroke or heart attack.  So how do you manage?  Know your triggers, focus on other things, practice proper breathing exercises, WALK, WALK, WALK, and have an emergency backup plan AKA (anxiety medication).


      As a busy working mom balancing work and life, I can tell you that the better you understand what sets in motion the attacks, the better equipped you will be to head them off at the pass.  You can control them, but you must be confident in that first.


      Mind & Body: When the feeling comes open the window, drink/sip some water, call a friend, pray, breath, walk, meditate or even sing.


      Triggers: STRESS!!!, caffeine, excitement (good news)…ect.


      Managing: Maintain focus (on something else or the feeling will own you and take over).


      Cut out triggers like coffee or sleeping pills (for a little bit). Make your doctor aware so that you can have a backup plan such as anxiety medication.



      1. Panic attacks can be delayed and can come from something stressful from a week ago.  Basically try to manage your stress.


      2. Walking regularly really puts those attacks in check.


      3. Panic Disorder is a little more intense with loss of hearing, vision, and possible fainting. They may feel like a stroke or heart attack and at this point you should have some sort of medication for them.


      4. Identify foods that trigger attacks and stay away from them.


      5. Remind yourself that you are not going crazy and you will not die from a panic attack, why do I say this?  Because unfortunately during an attack you actually do feel like you are fading away similar to what folks describe as dying.  Once you have established that confidence and know you are not dying, you will be able to manage a panic attack that is already in progress.


      Note: Not everyone experiences panic attacks the same way and not all of what is listed here will apply.

      Hope this was helpful.



  4. Coffee helps to prevent diabetes

    As i read in the comments above, coffee does help preventing diabetes. But too much coffee can also bring you others complications. An healthy body is a matter of balance. The key is an healthy diet to prevent developping diabetes.

    1. But it makes diabetes worse

      But it makes diabetes worse and makes blood sugar more difficult to control. It does that with normal subject as well.

    2. inhibit hIAPP with coffee

      Recently researchers have found that there are certain compounds in coffee that inhibit hIAPP (human islet amyloid polypeptide). It seems hIAPP is one of the causes for diabetes as it directly impacts the pancreas and the insulin producing capability.

  5. bleh

    Can you die from 2.5 cups of coffee if you are not a grown adult? (Not a child either, like 16) sorry that this is a stupid question…

  6. 5 hour energy

    I have found this post very helpful. I am a 29 year old adult male. I haven’t had any caffeine in at least 6 months. This morning I was very tired after staying up to late last night. I had such a
    busy day ahead of me at work, so I decided to try a 5 hour energy shot for the very first time. About 30 min after drinking it, I started feeling very dizzy, shaky, and light headed. I freaked out and had a panic attack. Luckily I was near
    A doctors office, and I went in. They said it was a caffeine overdose. I drank lots of water and felt a little better a few hours later,
    but still not great. I am now drinking a few beers to help calm my nerves. I’ll never drink a 5 hour energy again!

  7. Coffee Overdose – hell, don’t drink coffee anymore

    Drank a big cup of coffee with 30 teaspoons of expensive ground coffee. I think there was like 2000 g of caffeine in it. Result? Vomiting for 2 days. Extreme restlessness, nightmarish anxiety, constant pacing lasted 7 days. Anxiety, especially in the morning and mid-day lasted for more than a month. Never again. I overdosed on caffeine because I was trying to treat my Post-SSRI Sexual Dysfunction, coz I read that caffeine increases dopamine. Which did not work at all.

  8. Caffeine effects still lasting 3 days later anyone ??

    I went to the er Thursday night after feeling dizzy with a racing heart all test came back normal .. The doctor said he was pretty sure it was from the max dose I took of preworkout 5in a half scoops every 2 scoops was 100mg of caffeine . He also said it had other things in there that were pretty bad . It’s now Sunday and all though the muscle twitches and wired feeling have gone my heart tends to race (palpitations) sometimes when I get up to do things . I’ve drank tons of water . Has anyone else had lasting effects like this that took longer to go away ? I did not have this issue prior I’m sure I would have noticed considering I go to the gym my heart beat would me sky rocket .

    1. Very normal same thing happened here but its been 2 weeks and its just the panic attacks thats gonna be hard to get over other than that just convince yourself youre fine and everything goes away p.s: i went to 3 heart doctors all tests came back normal

  9. I didn’t know there was a

    I didn’t know there was a such thing as caffeine poisoning I just had a lot of caffeine because I wanted to stay awake but then started to feel really blugh then threw up a lot I took some activated charcoal and am just trying to wait it out is there something I can do to help push it out my system faster

  10. Caffine can be scary

    I overdosed on caffine. They rushed me to the er because my heart rate had been sitting at 190 for about an hour even whole I was laying down. They thought I was on cocaine bit no just caffine. The experience was awful though. I was red and sweaty. My vision was spotty. My chest hurt and breathing was difficult. They hooked me up to lots of meds to calm me and o drank a ton of charcoal. The moral is watch your intake. It is a drug. It also makes your brain activity drop, Especially in your frontal lobe. Ive had to cut it out entirely from my life cause it messed up my brain chemistry and my androgenic system pretty bad. Just be super careful. It can be dangerous and somtimes you get long term effects like my anxiety disorder.

    1. Decaf

      Though coffee has a lot of antioxidants and other nutrients, it has some awful consequences if not taken in moderation. Since am a coffee addict, I always try to take half regular and half decaf just to not to have some of those negative effects. But sorry for the unfortunate incidence that happened to you.

    2. symptoms

      Hey just wondering how long it took for things to go back to normal. I went to the hospital about a 2 weeks ago and my heart still feels kinda funny.

  11. Felt Immobile!

    This happened to me just yesterday and it brought me back to this forum! I don’t drink a lot of caffeine because I am so sensitive to it. I have been trying to get OFF it altogether but decided to have a coke with my lunch. Afterwards I went into the store to buy groceries and I suddenly felt immobile. Intuitively I knew it was related to the coke I had just drank. This has never happened to me before! Even though I could still actually move, it FELT like I couldn’t…and could not get myself to speak. I only shook my head and it FELT like I couldn’t talk even though I could. I thought I might be having a stroke but no paralysis. I know this sounds confusing but it’s the only way I know how to explain it. I came home scared and tried to rest and it finally went away, but my anxiety is thru the roof and I haven’t slept all night. I know I need to QUIT, but it’s such a struggle! The more I drink caffeine the more extremely sensitive I become to it.

  12. One different symptom

    Ok, I read all 26 pages of.comments and I did not see one symptom I recieved.. was on a road trip so had only 1 vivarin tablet with a large ice coffee and a 175 MG red bull within span of 3 hours. I felt great it kept me up and I felt excited and wake on the journey up. I was experiencing the heart racing and mind all over the place and the vibration feeling in leg and arm and pacing alot. Wasn’t 3 bad cause I googled it and found out its an overdose that the longest I’ve seen it last on here is for 3 days so I was calm.. My girl was here with me and calming me down and I tried to have sex and I couldn’t get hard.. never happened b4 and she tried very hard.. she said it was prolly cause I couldn’t focus so after trying for a hour she gave up.. I got up this morning cause I had to check so I started watching porn and I still didn’t get hard.. please tell me someone else experiencedo this and it goes away. Reply

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