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

Reduce your caffeine intake without pain and discomfort.

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  • Jim

    I’m 30 years old and don’t drink much caffiene. A friend talked me into drinking one monster, i did and my kidney hurt really bad for a day and a half. That can’t be good considering it takes 3 consecutive days of non-stop beer drinking to make my kidney feel that way.

  • Patrick

    If i drink them do my breasts still shrinkk even if im a guy??

  • fastmikebmx

    wow @ the dude who drank 6 red bulls for 5 years thats just asking for health problems 13 year old kid, i would say there is a 99.9 percent chance you will not die lol
    i have been drinking energy drinks for about a year now, but usually like two a day sometimes one, unless im out of town or something then i can go without. but yea i def do notice the addictive effects and the withdrawl effects even tho i dont consider myself to drink an excessive amount(once in a while maybe). i do feel a little tired if i dont have one and when i do have one i dont really get much of a boost i just feel normal. the normal feeling makes me want one(addiction). im starting to drink less tho, i drink them more now before doing something physical or if i go to a buffet or something and i stopped drinking coffee, maybe ill actually get a energy boost from them in the future!

  • kira

    I drink energy drinks and i sometimes feel the simtons but i trying to stop because i can see what it can do to u

  • niya

    i drink energy drink but i dont get none of these…

  • KeenTeens

    at my school not to be named , we drink energy drinks and get a buzz off of it for a short period of time and all of a sudden we feel really tired and fudgely want to go to sleep . is it normal to get cravings of food after we drink our energy drinks ? we’re not much of energy drink takers but is this normal ?

  • jibba jabba

    why drink the energy drinks ?
    water can give you a hit of fun .
    im no health freak but i do know energy drinks are no good . it rots you from the inside and thats bad .
    osteoporosis is a silent disease , which causes your bones to weaken and break very easy. and you get that from energy drinks .

    dont take it personal but i think its stupid how people and turn to energy drinks just to get a buzz out of it and not know the risks they’re taking .

  • kelsea

    ahhhh thank you so much. this helps my science fair research paper sooo much! 😀

  • melissa :)

    Hello def need to stop drinking caffine bevs:) if you know what i mean

  • OMG! Energy drinks are freakin’ bad for you it has many ways to kill you and to tell the truth it doesn’t do anything to your energy it’s you thinking it does i’m 13 and i have to tell ya’ll that(sad)…………..hahaha WOW!

  • mike

    I drank 4 four lokos yesterday and my heart was racing like crazy. Then earlier today I had a strange almost passed out moment(actually several). Never had that. I still feel crappy but screw goin 2 a hospital cuz they’ll run ekg tests on me. Not cheap w/o insurance. Anyone know wt I can do??? Help!

  • ted

    sounds like you have a virus or something…the caffeine would be out of your system a day later…not sure whats in Lokos though as I’ve never heard of it.

  • edjunkie

    4 four lokos! That is some serious alcohol intake(11%). I hate the fact that they don’t tell you the amount of energy type ingredients in these drinks not to mention the sugar content. That aside you should not still be feeling bad days later. Must be something else. You might just have a massive hangover

  • casey

    Okay, While energy drinks, of coarse, give us energy, I can see why all those side affects would occur. What I wonder is why would anyone want to sell a product that would cause such sucky affects?? Profits. Company’s wanna make money so they sell things that they know will attract the youth of today. So should we be holding those company’s responsible for making many have those side affects? Or do we shut our mouths, deal with it and still buy the drink?

  • smeegul

    i love energy drinks, and i know the health risks but i have yet to find another drink that taste like a monster, and im also doing a research paper over them so i know everything that can happen yet i still drink them… any ideas on how too stop, i usually drink about 15 a week

  • ted

    I don’t think you have to stop smeegul, the side effects mentioned above only happen after large quantities have been consumed. Just cut back to one energy drink a day. Moderation…..

  • Luke

    If I drink relentless or monster, the only side effects I get are tiredness and a need to pee. I don’t drink it often enough to have a built up immunity to it and I’m only 14- coming 15.

  • WV Girl

    ok my turn to comment, i’ve read 2 pages of comments about energy drinks and how there bad for u or don’t hurt u. ok 1. if they hurt u DON’T DRINK THEM. 2. MODERATION IS KEY HERE too many of them a day or week will hurt jus cut back on them addicting or not 3. DRINKING 1 EVERY NOW AND THEN shouldn’t be a problem except if u have heart problems but in that case jus avoid them. and last but not least if u have a probablem with them SO WHAT most people actually like having them around so stop tryin to get rid of them. me personally haven’t tryed all of them but red bull and nos are both good ( at least i think so).

  • Mr.Bond

    Dam man that’s messed up. You should sue the corp. But i just wanted to know, it seems these drinks are intense but only at the rate you were taking them its a shame somthing so easy to buy even by children could be so detremental to your health how many red bulls would it take to get a 135 pound 15 year old lad to get addicted?, and can the addiction be fatal?

  • Just

    Energy drinks?! There is no energy in them! Someone has created these poisons @ the expence of mainly of ur kidneys, ur cardiovascular organs & gi tract.It is a matter of time b4 they are all exposed.They’re only 10 yrs old.

Last Modified: November 10, 2017