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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  • Dove

    Just take a sip of palm oil and the itch goes away in a matter of minutes. Worked for me.

  • erm…my name is shelby and I like sugar

    I only really have energy drinks on a rare occasion, but you really should check the lable on your drink, especially if you’re diabetic. It could kill you. I know because my diabetic best friend topped herself on energy drinks. RIP jessica. But I get similar effects with or without energy drinks. Burst. Crash. Burst. Crash. It’s constant

  • i drink energy drinks about 4 times a year but i drink the monster size i love them they have lots of sugar and calories and bubles not something u can drink u gotta sip it taste so yummy….well my fav is monster and rock star
    love always cynthia go on you tube and look me up as 425cindy thanks for reading

  • i thought that all the energy drinks that the stores sell that wuld help for a little bit but eventually not after i read all the side effex and the ingredients.a lot of ppl think the energy drinks taste good but most of them taste like junk. redbull tastes like shit and other ones too. sometimes exept for monster. only the green one though.but since now i know wat is actually in monster, ill try to stop drinking them too.

  • paula

    hi what harm are they doing. I drink at least 8 snall tins. Of Sugar free energy plus are they sugar free drinks a day so thats 36 cans a week or how many is recomended too drink

  • Jon

    Energy drinks tend to mess me up a bit for a couple of hours after, depends how much I’ve eaten. This website however isn’t saying don’t drink them, it’s just be saying don’t be stupid and drink loads of them. If you drink too much Pepsi you’re gonna be ill, energy drinks just have a bit more caffeine in. Worried Mum, your sons not acting out coz he drank a red bull 4 days ago, he’s probably just a teenager, that’s like saying he once ate a mars bar and never been the same since. Everyone who gets addicted to these drinks too, just coz you have a problem doesn’t mean you should deny everyone else, the addictive part of them’s caffeine and sugar, you wouldn’t ban people having sugary coffee would you?

  • D. Buck

    I don’t like any energy drink but Venom. Monsters to overrated I think, plus I don’t think it’s as good as Venom. And I can drink about 2 or 3 a day before I feel weird. But i usually only drink about 4 per week. Maybe 6. I think it’s safe as long as you drink some water as well to flush out all the garbage.



  • Sam

    I have been drinking over 6 cans of relentless a day for the past two years and I have had no side effects, I can go without one for as long as I wish without headaches. When it comes to it its just if you are sensitive to caffeine and sugar No your limits LOL

  • Deane Alban

    I am so happy to have found this site. My adult son suffers from anxiety and panic attacks and he wont’ listen to me that drinking energy drinks could be causing them. I’m going to forward him this post. Hopefully he’ll listen to someone else! (Kids never listen to their mom, you know…)

    And a CHALLENGE to all the people who think they have no side effects from these drinks – stop drinking them and see how you feel. You’ll find out how truly addictive these drinks really are!

  • AJC

    I drink the energy drink supplied by my local superstore – it costs 35p a can and I really do enjoy the taste – I’ve never felt like I am flying or that its a pick me up, I just like the taste. I have also drank these for many years and whilst on the very rare occassion I do have a craving for one, I can take them or leave them. I have not experienced any side effects and usually drink 2/3 a day. Only thing I would add, is just be sensible and dont drink them too late in the evening, just in case they do keep you awake.

  • Susan Filek

    I woke up at 3:30am this morning, and took 600 mgs. of NoDoz caffiene pills. Instead of them waking me up, they made me feel incredibly woozy and stoned. I waited 2 hours, and at 5:00am I took another 200 mgs. of NoDoz. I felt even more woozier, and ended up sleeping for 4 HOURS! When I finally woke up, I still felt woozy and stoned. Later today around 3:30 pm I was dragging, so I took 500mgs. of NoDoz, and within a half hour, I was so woozy and stoned, I could barely stand up or keep my eyes open…I WAS TOTALLY GONE!!! What I don’t understand is…I take NoDoz almost everyday and they usually perk me up and help me get a lot of things done (full of energy)…so WHY did the NoDoz affect me in such an opposite direction? Just be warned, all who read this…DON’T MESS WITH ANY KIND OF CAFFIENE PRODUCTS!!! They can literally KILL YOU. By my testimony here, I SWEAR I thought I was gonna die today. STAY AWAY FROM THAT CRAP!!! It’s BADDDDDDD NEWS!!!!! Susan (grateful to still be alive)

  • Lorna

    Before I tell my little (its little fo sho :P) story… YES. IM THIRTEEN. Thats just so you know how stupid us thirteen year olds have become (: Anyway, At my school, The popular people (cheerleaders, jocks, and however we invite into our group) go to the mall EVERY FRIDAY to hang out. Our parents give us their credit cards and say “Go have a blast!” From 6:30 to 9 whenever the mall closes. At Yum Yo’s, a frozen yogurt place, also has monster and any other energy drink there that you can buy at ANY age 😛 So last Friday, I drank 12. I know. Pretty extreme. I started twitching, laughing uncontrollably, and fell into everything. I went to piss, and my piss was GREEN! I screamed “Holy shit! This looks like Shrek’s piss!” And flushed and ran out! No, I didnt have a heart attack or anything major. So get off my case. I have ADHD, So I dont crash afterwards 😛 Because I always have loads of energy. All my friends though crashed HARD. Im talking about 25 people at my house after the mall and they CRASHED.

  • anon

    ive had a can of mother almost everyday for the past year & have had only a few of the side effects described (apparently i had anxiety but because ive had issues with anxiety attacks before its hard to say if it was the energy drinks causing it or adding to the normal anxiety attacks id have). reason why: i did drink them in moderation and i would get about 3-4 hours exercise a day. main reason why people get sick off these things is they seem to go with the mentality “more is better” when in truth they should be thinking “all things in moderation”

  • Matt

    Thank good the tremor is a side-effect of energy drinks. I thought I had some disease all of a sudden and was REALLY SCARED. THANK GOD!!!

  • Janine


    I’m 16!… had TWO cans of Monster today… JUST TWO. I’ve always enjoyed them as they give me a good rush of energy. BUT today it was a different story 🙁 My friend noticed a change in my personality, but I couldn’t see it.. I just thought I was hyper. When I got home my parents noticed it too.. I felt fine.
    It was only as I sat still I could feel my whole body twitching and shaking, then I looked in the mirror.. What I saw wasn’t me, it wasn’t right! I went to bed thinking the feeling would pass, but I was so wrong! 🙁 My heart started pounding… I felt like I was DYING! 🙁 i’m ok now, but 2 hours later and i’m still shaking! IM NEVER HAVING ENERGY DRINK AGAIN!!!

  • Chloe

    Me and my friend (Both Aged 14) Had 8-9 Mother Energy Drinks And We HAd Heaps Of The Symptoms On There But Some.. It Was A Horrible NIght. I Was Holding A Door To Keep Me Up Etc BAD Headache ='( It was So Bad But I Still Drink Them…….. =(

  • For three years, I’ve moderately drank Monster. Maybe one a week. This summer, I switched to Rockstar. I’ve drank two almost every day and I’m fine. I love the crash I get because I have trouble sleeping. I love feeling jittery, and I don’t really get the hype I got when I first tried Rockstar. I don’t really have any side effects on that list, though. I do get shaky, though, and if I don’t drink them, I get really bad headaches. There were only a few times when I was overly-hyped and started truly getting panicky, but that was my own fault. They’re not too harmful, you just need to know how much caffeine your body can tolerate. Like, LOL. There are warnings right on the cans. If you can’t read, don’t blame the company.

  • Aza

    Im 21 and on average I drink between 2-4 500ml cans of energy drink a day and have been doing so for over 4 years. I can honestly say i have never suffered any of the negative effects listed here and i also never have any problems if i dont drink any for a few weeks. However caffeine and sugar both have no effect on me now i can drink a can of Monster as i get ready for bed and still fall asleep easily.

  • Addison

    I’m 16 and these drinks are most common among us teens and young adults, but my brother, age 25, dad, age 36, several friends of various ages, and myself consume Monster Energy Drinks on a regular basis, even multiple daily, and the ONLY 2 side effects I’ve noticed are acne breakouts when you consume a lot in a short period, and indigestion (which happens when consuming virtually anything.)

Last Modified: November 10, 2017