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Caffeine, Energy Drinks and Alcohol Interactions

Medically reviewed by L. Anderson, PharmD Last updated on Apr 9, 2019.

Caffeine is the most consumed drug on the planet. So it’s no surprise that energy drinks are the second most popular dietary supplement in the U.S., second only to vitamins. Effective marketing has skyrocketed the sales of these products, including popular brand names of energy drinks such as:

  • Red Bull
  • Amp Energy
  • Monster
  • Rockstar
  • NOS
  • 5 Hour Energy Drink energy shots

Annual sales of energy drinks number in the billions of dollars worldwide.

Caffeine is the main ingredient in most energy drinks, and a 24-oz energy drink may contain from 80 mg to 500 mg of caffeine (similar to that in four or five cups of coffee).

Energy drinks may also contain guarana (a plant-based source of caffeine also called Brazilian cocoa). One gram of guarana is equal to 40-50 mg of caffeine, and although it may be listed as an ingredient in some energy drink labels, it’s added caffeine content often is not noted on the label. Other ingredients may include taurine, B vitamins, sugar, ginseng, artificial sweeteners, or artificial preservatives and colors.


  • Stimulates the central nervous system
  • Imparts a temporary sense of alertness
  • Dilates blood vessels
  • Elevated heart rate
  • Elevates blood pressure
  • Can lead to dehydration
  • Leads to withdrawal symptoms

While caffeine is used responsibly and safely, some people misuse energy drinks by combining them with alcohol to heighten a sense of intoxication. Combining alcohol with energy drinks that are high in caffeine or guarana has become popular among a younger crowd. Males between the ages of 18 and 34 years consume the most energy drinks, and about 30% of teens drink them on a regular basis.

  • A study in the journal Pediatrics found that 54% of 496 surveyed college students reported mixing energy drinks with alcohol, and 49% drank three or more energy drinks mixed with alcohol at one setting.
  • The U.S. Centers for Disease Control (CDC) published in 2015 that 13% of students in grades 8, 10, and 12 and 33% of young adults aged 19 to 28 reported consuming alcohol mixed with energy drinks at least once in the past year.

Safety concerns of mixing alcohol with caffeine, such as that found in energy drinks:

  • Caffeine can be stimulating and can block the sensory cues used by people to know they are getting intoxicated. They may drink more alcohol and worsen their impairment, increasing the risk of alcohol-linked injury.
  • Some people believe caffeine will counteract the alcohol effect, but that is not accurate. Caffeine cannot “sober up” someone up who has been drinking alcohol. Their judgement, coordination, and reaction time are still adversely affected.
  • Injury or death can occur because people may be more likely to engage in risky and hazardous activities. Studies have shown alcohol poisoning, unprotected sex, sexual assault, and riding with an intoxicated driver occur more frequently.
  • For some people, excessive amounts of caffeine can lead to health issues such as heart problems (fast heart rate, altered heart rhythm, increased blood pressure), headaches, anxiety, sleep problems (insomnia), dehydration, or agitation.
  • Many caffeinated drinks contain 25 to 50 grams of sugars, and when added to additional calories from alcohol, can be problematic for diabetics and those with weight concerns.
  • As reported by the NIH, 42 percent of all energy-drink related emergency department visits involved combining these beverages with alcohol or drugs (including illicit drugs like cocaine, central nervous system stimulants like Ritalin or Adderall, or marijuana).

Groups for which energy drinks have warnings:

The American Academy of Pediatrics reports that caffeine has been linked to a number of harmful health effects in children, including effects on the developing neurologic and cardiovascular systems. They do not recommend caffeine for children. Most energy drinks are labeled to be avoided in children, as well.

If you have an underlying condition such as heart disease or high blood pressure, ask your doctor if energy drinks may cause complications.

Women who are pregnant or breastfeeding should avoid or limit consumption of these beverages.

Bottom Line

Energy drinks may temporarily enhance alertness, but the individual effect when adding alcohol to an energy drink can be problematic. Young adults who combine caffeinated energy drinks with alcohol may not be able to judge their level of intoxication. Sleep can be disrupted and risky behaviors may seem harmless, leading to injury. Health care providers and parents should discuss the use of caffeine and alcohol with adolescents and young adults, and educate on the potential risks of either one, either alone or mixed together.

A daily coffee or two is a ritual for many adults, However, energy drinks, which can be exceptionally high in caffeine, should be used with discretion and should be avoided with certain health risks. If you have a heart condition or high blood pressure, are pregnant or breastfeeding, are a teen or a parent of a child, discuss with your doctor if caffeine-boosted energy drinks are wise for your health.

Avoid regularly mixing alcohol with caffeine. If feeling run down or fatigued, consider healthier ways to boost energy, such as adequate sleep, daily exercise, and a healthier diet.

Other Alcohol Interactions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.