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Energy Drink Side Effects

28 Oct Posted by in Energy Drinks | Comments


Are there side effects from the ingredients in Energy Drinks?

As the safety of an energy drink debate rages on, we thought we would take a look at what harmful consequences could result from consuming to many energy drinks.

It’s important to understand that energy drinks contain supplements and therefore, most brands contain some type of warning label about consuming more than the recommend serving. In moderation, most people will have no adverse, short term side effects from drinking energy drinks, however, the long term side effects from consuming energy drinks aren’t fully understood as of yet.

We will take a look at the most common energy drink ingredients and list the potential side effects that could result from ingesting too much of them through your favorite energy drink.

Energy Drink Side Effects

Recent research in Australia has highlighted the risks with over-consumption of energy drinks. This data was gathered from 7 years of calls the the Australian Poisons Center. Listed in order of most common to least common.

  • Palpitations / tachycardia
  • Tremor / shaking
  • Agitation / restlessness
  • Gastrointestinal upset
  • Chest pain / ischaemia
  • Dizziness / syncope
  • Paraesthesia (tingling or numbing of the skin)
  • Insomnia
  • Respiratory distress
  • Headache


Of course this is the most common energy drink ingredient and most of you know the side effects, but the list wouldn’t be complete without it. Caffeine can be disguised as guarana,  green tea extract, and coffee extract so be aware of this when reading energy drink labels. Caffeine can produce the following side effects;

  • 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.
  • Headache and severe fatigue from withdrawal.
  • Breast shrinkage in females.

It’s hard to pinpoint a safe dose because it varies from person to person and according to a person’s tolerance. Between 500 milligrams to 1000 milligrams in a 24 hour period will probably result in some of the above side effects.


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” or they’ll call it “glucose”. High sugar drinks are linked to the obesity epidemic and the rapid increase of type 2 diabetes. The sugar in energy drinks causes insulin spikes which later result in a “crash like” feeling.


No side effects from Taurine 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.

B Vitamins

  • More than 35mg of Niacin (B3) can cause flushing of the skin. Intake of 3000mg or more can result in liver toxicity.
  • More than 100mg of B6 can cause sensory nerve problems (burning sensation) or skin lesions.


No known side effects have been reported, but 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; nausea, diarrhea, headaches, nose bleed, high blood pressure, low blood pressure, and breast pain.


While no side effects have been reported there’s still debate on its safety which has lead Canada, England, Germany, and France from allowing it in non-prescription products.

Artificial Sweeteners

If you like the sugar-free energy drinks variety there is ongoing debate over the safety of these. Here’s  good article from diet-blog on the subject.

Ginkgo Biloba

  • nausea, vomiting, diarrhea, headaches, dizziness, heart palpitations, and restlessness.
  • Can interact with other medication such as blood thinners and anti-depressants.


  • vomiting, nausea, headache, diarrhea, stuffy nose, restlessness and sleeping difficulty.


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.


Its important to note that with some of the energy drink side effects many ingredients can have similar negative effects, so with much of the information being anecdotal from patient’s records, it’s hard to say which ingredient actually caused the problems if the patient was ingesting several combinations of these at one time.

I think, overall, the evidence supports the safety of energy drinks within the context of moderation and knowing your body i.e. allergies, tolerance etc. However, we still don’t know any long-term energy drink side effects that could result, if any, because energy drinks haven’t been around long enough to draw any conclusions from their long-term effect on the human body.

If you drink responsibly and use energy drinks when you need a boost of energy and not use them as a replacement for water, then you most likely will avoid energy drink side effects.


The Mayo Clinic 

The National Institutes of Healt