Energy drinks come with some potentially serious health risks. But it’s not clear whether drinking them on an empty stomach increases the effects or their severity.

Whether you’re studying for a final exam or working an early morning shift, energy drinks can help you stay alert and focused. They may contain high doses of caffeine (a stimulant) along with sugar and other additives.

Here, we explore the potential dangers of consuming energy drinks on an empty stomach.

Research suggests that energy drinks can pose significant short-term health risks. If you drink them on an empty stomach, their contents will be absorbed into your bloodstream very quickly, which could increase the risks.

According to a 2023 research review, energy drinks have been linked to medical emergencies such as:

Caffeine overdose

The Food and Drug Administration (FDA) recommends that healthy adults limit their caffeine intake to 400 milligrams (mg) per day, which amounts to 4–5 cups of coffee.

Energy drinks can contain 40–250 mg of caffeine per cup. If you drink one or more of these beverages without food in your stomach to slow down your caffeine absorption, you could overdose.

Cardiovascular problems

Caffeine is a stimulant that can speed up autonomic nervous system functions such as your heart rate and blood pressure. And you might be more likely to feel the cardiovascular effects of caffeine if you consume it on an empty stomach.

The authors of a 2017 review found that irregular heart rhythms (arrythmias) were the most common heart-related complication of energy drink consumption.

Other reported cardiovascular problems included:


Caffeine is a diuretic, which means it makes you produce more urine than you usually would.

Indeed, dehydration is a commonly reported side effect of energy drink consumption, according to the authors of a 2021 review that analyzed the negative effects of energy drinks as reported in 32 studies.

Energy shots, in particular, typically contain a high dose of caffeine in relatively little liquid. They may be more likely to cause dehydration, especially when consumed on an empty stomach.


Some people find that consuming too much caffeine gives them a headache, a symptom that is often a result of dehydration.

In the 2021 review mentioned above, headaches were among the most frequently reported side effects of energy drink consumption, affecting around 18% of participants in the 32 studies the authors examined.

But it’s not clear whether you’re more likely to experience a headache if you have an energy drink on an empty stomach.

Upset stomach and other digestive issues

The ingredients in energy drinks can irritate your gastrointestinal (GI) tract. The authors of the same 2021 review found that about 22% of participants in the featured studies experienced an upset stomach.

According to research reviews from 2017 and 2023, other digestive issues that have been linked to high caffeine intake include:

  • abdominal pain
  • gastritis
  • GI upset
  • nausea
  • vomiting

Kidney or liver problems

The authors of the 2023 review note a link between energy drinks and kidney problems, including kidney failure. Additionally, they mention a connection between two other conditions that are sometimes related to kidney issues: hyponatremia and rhabdomyolysis.

The authors propose that this side effect may be due to large doses of ingredients that can harm the liver, such as caffeine and vitamin B3.

Stress, restlessness, and insomnia

Caffeine and sugar may temporarily increase energy, but many people report an accompanying sense of anxiety or restlessness that may get in the way of sleep.

In the 2021 review, these symptoms were among the most frequently cited among children and adults who consumed energy drinks:

  • difficulty sleeping (insomnia) in 35% of study participants
  • stress in 35% of study participants
  • jitteriness, restlessness, or shaking hands in 25% of study participants
  • a “jolt and crash” sensation in 23% of study participants

It’s not clear whether these symptoms would be more noticeable if you consumed energy drinks on an empty stomach.

The American Academy of Pediatrics recommends that children and teens avoid energy drinks altogether because of their high caffeine and sugar content.

Although these drinks remain popular with young adults, the authors of a 2017 review found that they were linked to a variety of negative health events in people of varying ages, including:

  • rapid heart rate
  • vomiting
  • seizures
  • death

More research is needed on the long-term effects of energy drinks on children’s development.

While you may find yourself drinking them on an empty stomach from time to time, these beverages aren’t the best options when you haven’t eaten:

  • Juice: Many types of juice are acidic and can irritate your stomach lining if you drink them on an empty stomach. In addition, the sugar content in juice causes a spike in blood sugar.
  • Soda: Like juice, soda contains a lot of sugar. It can cause your blood sugar to rise quickly and crash, leaving you feeling tired.
  • Alcohol: Drinking alcohol on an empty stomach can increase your risk of intoxication.

Keep reading to learn more about energy drink safety.

Are any energy drinks safe for kids?

Many energy drinks contain large amounts of caffeine and sugar and are therefore not safe for kids. The American Academy of Pediatrics recommends that children and teenagers avoid energy drinks altogether.

Can energy drinks damage your stomach?

Drinking them too often might damage your stomach. While this side effect hasn’t been widely studied, the authors of a 2020 case study described a person who developed stomach inflammation after prolonged energy drink consumption.

Why do I feel sick after drinking an energy drink on an empty stomach?

The ingredients in energy drinks can cause your stomach to produce excess acid, which could give you heartburn or leave you feeling bloated or nauseated.

Should you drink caffeine on an empty stomach?

Caffeine’s effects might be more noticeable if you consume it on an empty stomach. But it’s probably fine to consume small amounts of caffeine on an empty stomach as long as you’re staying hydrated and eating regularly.

Energy drinks may contain large amounts of caffeine, along with sugar and other additives. While they might give you a quick boost of energy, they come with a risk of side effects.

The possible side effects might be more severe if you consume energy drinks on an empty stomach. Some of the most commonly reported side effects are irregular heart rhythms, GI upset, and anxiety. But these effects are not necessarily related to drinking energy drinks on an empty stomach.