Mixed Caffeine and Alcohol Drinks Raise Intoxication Risk

It’s a common night out move: chasing beer or liquor with an energy drink or coffee cocktail. But if you’ve ever felt surprisingly wasted after one too many ‘caffeinized’ cocktails, science now confirms your instincts were right. A major study from the University States reveals exactly how much riskier these mixed drinks really are—and why your brain might be lying to you about how drunk you actually are.

If you mix caffeine with alcohol, you're three times more likely to reach dangerous levels of intoxication—and significantly more likely to drive drunk or take other risks—compared to drinking alcohol alone. That’s the finding from a survey of over 800 bar patrons, backed by measured blood alcohol levels.

What the Study Found on Caffeine and Alcohol Mixing

Researchers from the University of Florida published their findings in the journal Addictive Behaviors, based on direct interviews and breath or blood alcohol testing with more than 800 people at bars. They compared individuals who consumed alcohol alone with those who combined it with caffeine-containing drinks like coffee, energy drinks, or caffeinated sodas.

The results were clear. People who mixed caffeine and alcohol were three times more likely to report being heavily intoxicated. More alarmingly, this group also showed a far higher tendency to engage in risky behaviors—including drunk driving.

Why Caffeine Masks Your True Drunkenness

Caffeine is a powerful stimulant. When you drink a caffeinated alcoholic beverage, the caffeine blocks some of the adenosine receptors in your brain—the ones that make you feel sleepy or sluggish when you drink. This means you can feel more awake, alert, or even sober, even though your blood alcohol level is just as high—or higher—than if you hadn’t had any caffeine.

This false sense of sobriety leads to a dangerous disconnect. You may think you’re in control, that you can drive home, or that you can handle more drinks. In reality, your coordination, judgment, and reaction times are still heavily impaired by the alcohol.

The Misjudgment Effect: Overdrinking and Risk-Taking

Because caffeine dulls the usual cues of intoxication—like drowsiness or slowed thinking—people mixing the two tend to drink more than they otherwise would. They underestimate how drunk they are and overestimate their ability to function. That leads directly to increased risk-taking: from getting behind the wheel to engaging in other unsafe behaviors.

The Florida researchers emphasized that the caffeine doesn't reduce your blood alcohol concentration—it just changes how you perceive it. That perception gap is what makes mixed drinks especially hazardous.

Frequently Asked Questions

Does caffeine actually reduce drunkenness?

No. Caffeine does not lower your blood alcohol level or reduce actual intoxication. It only masks the feelings of tiredness or sedation, making you feel more awake even when you're still highly impaired by alcohol.

Why are caffeine-alcohol mixes more dangerous?

They trick your brain into feeling soberer than you are. This leads people to drink more, underestimate their impairment, and take dangerous risks like driving, all while their actual blood alcohol level remains dangerously high.

How much more likely are you to get drunk when mixing caffeine and alcohol?

According to the University of Florida study, people who consume caffeine with alcohol are three times more likely to reach a state of severe intoxication compared to those drinking alcohol alone.

Are energy drinks with alcohol especially risky?

Yes. Energy drinks typically contain high levels of caffeine, which strongly mask alcohol’s sedative effects. This makes it even harder to gauge your true level of impairment, increasing the chance of dangerous decisions.

Is drunk driving more common among those who mix caffeine and alcohol?

Yes. The study found that people who mixed caffeine and alcohol reported significantly higher rates of behaviors like drunk driving, due to their underestimated level of intoxication.