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.

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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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  • Shane

    Niacin is B3, not Thiamine. Thiamine is B1. It is the B3/Niacin that causes your skin to turn red. A lot of companies offer “flush free” niacin now due to this fact.

  • ted

    Noted Shane, you are right don’t know how I or no one else has spotted that before… Thanks.

  • Paul

    I used to consume a couple cans of any type of energy drink you can imagine within a week or so. I loved the buzz and I never had any side effects from drinking them. Maybe it’d make me drowsy later, but I felt fine. It wasn’t until halfway through college when my stomach would turn after drinking a can of Monster. Eventually, after drinking another can a few weeks later did I realize that something was horribly wrong. The drink went right through my system, with a burning feeling , coming out of my system exactly the same as how it looks in the can. I stopped getting the caffeine buzz and I’ve tried a lot of energy drinks. The only one that doesn’t bother me at all anymore is Monster Java. Starbucks Double Expresso also doesn’t give me bad side effects, and that’s the brand my college sponsors, so it’s hard to find any Monster Java around there.

  • Jordan

    Honestly, i’ve had major mood swings in the past week or so. And I think it is directly related to my energy drink consumption.

  • Md. Iftakhar Islam

    Here in My country there is about 4/5 brand common energy drink . I saw young’s to drink those on streets . I tried 2 times naming “Tiger ” , wakkkkk thuuuuuu . That is like the cough syrup i got with my tongue ,its a bad smell .

    But i also found that those bottles are not printed with the ingredients . its really so sad for the health & safety issue in the country like a 3rd world .

  • Junaid

    Its happened with me.1 day i consumed 1250 mililitre of sting.and at that night i felt nausea, my tongue became white with layers, blood pressure became unstable. . .

  • dan

    I used to have erectile dysfunction ,after drinking lots of monster (3 cans a day) I dont and the effects last(I havent been drinking them as much.So there-

  • Mike

    I on’t drink energy drinks every day or week. Some weeks none,some 1 andthen there is some weeks where I have like 3 or 4 type thing allways one a day thought. If I am consuming energy drinks offten what could happen? 1st week of september I had one or two 12 oz cans,next week ha one 16oz can and last week had two different 16oz cas one was sugar free and then between 2 or 3 days drank one that only comes in 24oz botle’s. Plus i have a full 16oz can for the upcoign week and ws thinking of mabyegetting 12 more for the week.

  • Mike

    meant 1-2 more for the week NOT 12

  • If possibly energy drinks have much much of these adverse effect on human health then all caffiene energy drinks should be destroyed banned on all markets

  • james murry

    yeah well, i drink almost 5 cans everyday i only get a buzz every so often and apart from that i dont have any side effects, the other day when i shagged my girlfriend i had four cans of monster and still managed to get an erection, i dont understand how any of this BULLSHIT, makes sense please get back to me…

  • j dub

    i have been drinking AT LEAST 1 energy drink a day for the last 4 years. im as immune as could be to the “energy” effect of the drink but continue to drink them as to not the the caffeine headaches. i dont wanna sound too melodramatic, but if i could do it over again, i would. think of all the money i wasted on these things…. sheesh…

  • Jade

    I drink mother daily as many as i can get my hands on, and my friends give me a fair bit of shit over how bad it is, imnit sure what the side effects are but I feel fine!

  • Yamahiney

    I used to drink 4-5 cans of java monster a day, they’re my favorite drink, but since i’ve stopped drinking them, everytime i drink something with caffeine it gives me the shits and it makes me nausous and nearly throw up everytime..

  • Nunyabweesnesses


  • miles

    i drink 1 green monster a day and i am 16 years old and never have any side effects from it i love monster and will die drinking monster..

  • Bryan

    miles your crazy, you need to have atleast 2 a day to have any side effect

  • Wolfe

    All the hypothetical problems with energy drinks are all unproven. The simplistically put problems are overdosing on the supplements within a given energy drink ( so don’t overdo them ) and staying hydrated by at least matching your intake of an energy drink with an equal amount of water ( preferably double ).

  • shut up!!

  • Cortney

    Hi I’m using your information in a reasearch paper for a class of mine and i need to cite this information, so I would like to who the author is and when this article came out.

Last Modified: November 10, 2017