Energy Drink Side Effects

Energy drinks can have potential side effects if not consumed responsibly or as directed.

Energy Drinks

Because of the vast array of ingredients in Energy Drinks, it may make them more likely to produce side effects than beverages containing just caffeine alone.

What’s worse, the safety of energy drinks has become a major issue as consumption has increased among children and teens.1

Top 10 Energy Drink Side Effects

Recent research in Australia2 has highlighted the risks with over-consumption of energy drinks. This data was gathered from 7 years of calls to the Australian Poisons Center.

Listed in order of most common to least common:

  1. Palpitations / tachycardia
  2. Tremor / shaking
  3. Agitation / restlessness
  4. Gastrointestinal upset
  5. Chest pain/ischemia
  6. Dizziness/syncope
  7. Paresthesia (tingling or numbing of the skin)
  8. Insomnia
  9. Respiratory distress
  10. Headache

The Center for Food Safety Adverse Event Reporting System (CAERS) received over 140 complaints about adverse side effects from 5 Hour Energy, Monster, and Rockstar over the last 10 years. Some of these resulted in hospitalization and death. See the report here.

If you’ve experienced other energy drink side effects tell us about them in the comments below.

Energy drinks contain supplements, herbs, and vitamins and are required to list warnings on the label about consuming more than the recommended serving.


Potential Problems from the Specific Ingredients

In moderation most people will have no adverse, short-term side effects from drinking an energy drink, however, the long-term side effects of consuming energy drinks aren’t fully understood as of yet.

wean caffeine

However, if you have reached a state of dependence on energy drinks, then it’s time to start considering products specifically designed for helping you kick caffeine without withdrawal. Of those out there, we endorse Wean Caffeine which is highly effective and inexpensive.

Let’s take a look at the most common energy drink ingredients and list the potential side effects that could result from ingesting too much.


This is the most common energy drink ingredient and one of the most widely consumed substances in the world.

Caffeine tolerance varies between individuals, but for most people, a dose of over 400mg/day may produce some initial symptoms: restlessness, increased heartbeat, and insomnia.

Higher dosages can lead to:

  • Increased blood pressure
  • Heart palpitations
  • Anxiety and panic attacks
  • Gastrointestinal disturbance (diarrhea)
  • Increased urination
  • Dizziness, irritability, nausea, nervousness, jitters
  • Allergic reactions can include; rash, hives, itching, difficulty breathing, tightness in the chest, swelling of the (mouth, face, lips, or tongue), diarrhea, shakiness, trouble sleeping, vomiting
  • Headaches and severe fatigue from withdrawal
  • Painful withdrawal symptoms

(Read more about caffeine overdose here)

Caffeine can be found in other natural ingredients such as guarana,  green tea extract, and coffee extract or can go by many other names, so be aware of this when reading energy drink labels.

Please consult the caffeine database for an exhaustive list of caffeine in energy drinks (and other drinks). This is updated weekly.

Adrenal Fatigue

There is debate as to whether adrenal fatigue is a real disorder, but here’s what some think happens.

Some people can become tired even after consumption of caffeine. This is believed to be a symptom of adrenal fatigue where the body’s aadrenalinesystem has become overtaxed by the constant high caffeine intake.

The solution is not to increase caffeine even more – but to reduce, detox, and get the adrenal glands back to a healthy state.

Remember, it’s hard to pinpoint an exact safe dose because it varies from person to person and according to a person’s tolerance.

See our Caffeine Safe Dose Guide here.

Between 500 milligrams to 1000 milligrams in a 24 hour period will probably lead to some of the more severe side effects.

Click here to find out how much caffeine in different energy drinks would be deadly.


Most energy drinks are high in sugar in the form of high fructose corn syrup and/or cane sugar. Some use creative names to make their version of sugar seem “healthier”, like “natural cane juice”.

  • High sugar drinks are linked to the obesity.
  • Sugar causes tooth decay
  • Increases risk of type 2 diabetes.
  • The sugar in energy drinks causes blood sugar and insulin spikes, which later result in a “crash-like” feeling.
  • Sugar is also somewhat addictive.


No side effects from the Taurine3 in energy drinks have been documented.  Some countries (France, Denmark, and Norway) originally banned energy drinks because of their taurine content, but have since accepted that taurine consumption is safe based on the evidence to date.

The amount placed in energy drinks is well below what would be needed for therapeutic benefits or for any potential side-effects.

B Vitamins

  • More than 35mg of Niacin (B3) can cause flushing of the skin. Intake of 3000mg or more can result in liver toxicity. The British Journal of Medicine recently published a case study of a man who consumed about 5 energy drinks a day for a period of three weeks. This caused toxic levels of niacin to build up in his body, leading to nonviral hepatitis.  The unidentified energy drink in question supplied 200% of the RDA of B3. A summary is found here.
  • More than 100mg of B6 can cause sensory nerve problems (burning sensation) or skin lesions.


No major side effects have been reported, but it could cause dizziness, tiredness, headaches and an upset stomach. (src.) Ingesting large quantities has been linked to diarrhea. Large doses have been used to treat certain psychiatric disorders.


  • Some studies have linked it to sleeplessness, while others refute this.
  • Other possible symptoms include; low blood pressure, edema, palpitations, tachycardia, cerebral arteritis, vertigo, headache, insomnia, mania, vaginal bleeding, amenorrhea, fever, appetite suppression, pruritus, cholestatic hepatitis, mastalgia, euphoria, and miscarriage.


While no side effects have been reported, there’s still debate on its safety.4  Many countries including Canada, England, Germany, and France have concluded that it is not a safety concern.

Artificial Sweeteners

If you drink sugar-free energy drinks you may be consuming any number of artificial sweeteners. There is always debate around the negative health effects of these (particularly aspartame5).

However, all major health institutions regard them as safe.

Ginkgo Biloba

Gingko is a herb, and can cause some minor side effects in some people6:

  • nausea, diarrhea, headaches, dizziness, heart palpitations, and restlessness.
  • Can interact with other medication such as blood thinners and anti-depressants.
  • A recent study found that ginkgo caused thyroid cancer in rats.


Too much of this amino acid can cause vomiting, nausea, headache, diarrhea, stuffy nose, restlessness and sleeping difficulty.7


This amino acid is derived from green tea and many energy drinks and shots have begun putting “green tea extract” in their products.

It produces a different type of alertness than caffeine and there hasn’t been any scientific evidence of it causing adverse side effects. Some have reported feeling light-headed when consuming a dose of more than 300mg of L-Theanine.8

What is Safe For You?

Energy drinks probably shouldn’t be a staple of anyone’s diet and coffee is certainly a healthier source of caffeine.

However, despite a number of alarming reports of overdose in recent years, for most people energy drink consumption is fine in moderation.

Many reported side effects are anecdotal – being reported from patient’s records. So, it’s hard to say which ingredient actually caused the problems if the patient was ingesting several combinations of these at one time.

Be Careful of Pre-existing Conditions

If you or your child has a pre-existing heart condition of any sort – they should not be consuming energy drinks.

In general, it is better to avoid the larger drinks (i.e. Mega Monster has a massive 240mg caffeine in its 24 fl oz giant can) and stick to smaller 8oz cans.

If people drink energy products responsibly and use energy drinks occasionally, then most will likely avoid any of the energy drink side effects.

Get Help Quitting Caffeine

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  • Gilly

    I don’t think I’d ever read that breast-shrinkage article before, haha. I just about keeled over laughing. It’s bad! But…wow.

  • bob

    All I know is my member is now shorter than before I drank so many energy drink. On the plus side though the girth has more than tripled leving it looking like a cheese wheel

  • 3ntropy

    I was looking for an article that i thought i read ages ago about the negative effects of taurine and Alzheimer’s disease; however i must have read it wrong because all of the stuff i find on the web says that taurines not only good for Alzheimer’s; but heaps of other stuff too ( As a side, side note as well research shows that caffine (five coffee cups a day)actually reverses Alzheimer’s (, with the increase in those with Alzheimer’s maby one day we could get a prescription and discount on energy drinks 🙂

  • gustof

    I drank 4 rockstars and 2 red bulls and i couldnt walk straight from being to dizzy. I peed every 30 seconds for like an hour and my tummy hurt for a day. My head was throbing and i was as tired really tired after 3 hours of drinking them all the drinks were 64.4.oz of pure energy oh and i was about to throw up 15 times but never did. =]

  • Kyle

    I drink alot of monster energy and i dont get these side effects and im only 11

  • chrislastnamerperson

    i am 11 years old and one day when i was 10 i drank so much bawls that i was bouncing off the walls but i didnt have any side effects

  • Ol’ What’s his nuts

    Being a kid helps, Kyle and Chris. You guys are young enough that while you may not have a high tolerance, your bodies are resiliant and in a near constant state of growth. In other words: you’re kids, therefore you’re tough.

  • Ol’ What’s his nuts

    I forgot to mention: THAT DOES NOT MEAN TO GO CRAZY! You’re smaller, higher doses that an adult could take (with side effects) could kill YOU. Be careful!

  • This gives us a lot of good information for our science project. 🙂

  • Allie

    Where the hell was i when they did hte study about breast shrinkage?! sure as hell hasnt done anything for me -__-

  • D

    Ah, you guys are a bunch of wussies. I usually drink 5+ energy drinks a day along with a pot or more of coffee. Side effects? What side effects? When you’re putting that much “energy” into your body, you eventually build up a tolerance. I can easily consume 500mg of caffeine and be sleeping like a baby 10 minutes later. The only time I ever notice any negative side effects is when I don’t consume ANY coffee or energy drinks. Withdrawl is a biach.

    On the plus side: coffee and a number of energy drink components are known to have several beneficial effects. I suppose you should probably avoid the stuff if you’ve got a weak heart, but otherwise I’d say they’re just as safe as a cup of coffee and a daily vitamin.

  • Bob

    D, you’re going to get adrenal gland fatigue if you don’t have it already

  • Bryan

    Wikipedia as a source? #FAIL.

  • i love energy drinks i could drink them forever when i drink energy drinks it feals like am flying weeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eh eh aha it rainen

  • D,
    MODERATION MAN!!!!! The only reason you get those negative withdrawal side effects is because you are addicted to a lot of chemicals. Caffeine is a psychoactive stimulant drug. You can get addicted to mild drugs just like hard drugs. Pretty soon you won’t be able to get “energy” from it. You have to keep drinking more. And where are you going to be when you have to drink 12 pots of coffee and 16 energy drinks a day? Peeing yourself dehydrated. Clean out your body and have a glass of water.

  • misty

    i have been drinking alcohol these past 6 days and going to work in the day with only having two hours or so of sleep so i buy 3 or 4 rockstars @473 ml a bottle and today i can barely breath and my nose hurtw to breath out of i feel like iv beeen sniffing so much coke my head is gonna explode and last night when i went to bed i kept twitching i feel out of it and im coughinng up blood and pissing blood pretty sure thats a problem im hopeing it will go away in the next day im jsut gonnna drink alot of water and take some multi vitamins i also have only ate a pita burgeer and poutine in the past 5 days i cant keep a thing down and today i barely was able to get down 4 potatoe wedges neverr drinking that many rock starss EVER again

  • ted

    It sounds like you have a nasty virus or something, I seriously doubt the Rockstar had anything to do with it. You should go see a doctor especially since you are coughing up and pissing blood.

  • Jason

    I used to drink energy drinks all the time. Sometimes I would have 6 or more redbulls in a day. And I did this for almost 5 yrs straight. Now, I just recently discovered, that I have a heart condition called VPC (Ventricular Premature Contraction). It basically means that every few minutes my heart will stop for about a second. People say that there is no issue with energy drinks. But I am one person that can say that is completely not true. Because of all the energy drinks I used to drink, I can’t have them anymore. If I do there is a good chance that my heart will stop and may not start again. Just sayin is all

  • Tyler13

    Can you die after drinking a monster? Oh and I’m 13 soo I want an accurate answere!

  • Tyler13

    Can you die after drinking a monster? Oh and I’m 13 soo I want an accurate answere!

Last Modified: November 10, 2017