The Myth Is False: Caffeine Will Not Sober You Up After Drinking Alcoholic Beverages

Drinking strong coffee at the end of a night of heavy drinking to "sober up" is a time-honored (but unproven) practice.

Contrary to popular belief, caffeinated beverages — including increasingly popular energy drinks — do not counteract the effects of alcohol and will not help someone who has been drinking alcohol "sober up" or be fit to drive.

Energy drinks often contain caffeine, but they may also contain a variety of other substances including taurine, guarana, ginseng, vitamins and sugar. Some energy drinks have contained both caffeine and alcohol, and although at least some of these drinks have been withdrawn from the market, others continue to be available.

By itself, alcohol — even in modest doses — has well-known negative effects on alertness and attention, and people who have been drinking alcohol show reduced performance in tasks such as reaction time and other important measures of driving ability.

Ingesting caffeine alone, on the other hand, has been shown to have the opposite effects and tends to increase alertness and performance.

It would seem logical that caffeine should be the perfect antidote to alcohol, and in fact there is evidence suggesting that caffeine can reverse some of the adverse performance effects of alcohol, particularly in people who have ingested only a small amount of alcohol and have "legal" blood alcohol levels.

However, there is no evidence to suggest that caffeine can convert an intoxicated person into a sober one.

Indeed, caffeine cannot be counted on to counteract the most important negative and dangerous effects of alcohol, namely the ability of alcohol to impair performance in tasks related to driving. Caffeine does not appear to neutralize other negative effects of alcohol intoxication on driving safety, such as increased risk-taking and impaired judgment.

A recent study looked at the effect of an energy drink containing 6 percent alcohol (as well as caffeine) on cognitive performance, and found that the caffeine and other stimulants in the energy drink did not overcome the negative effects of alcohol.

Can caffeine cause a person to feel less intoxicated?

Some studies suggest that caffeine can reduce a person’s perception of being intoxicated following alcohol ingestion.

This is the worst possible combination — the intoxicated person has a reduced feeling of intoxication but does not obtain any effective reversal of the detrimental effects of alcohol on areas such as driving ability.

So while there is certainly nothing wrong with having caffeinated coffee instead of another drink of alcohol before you leave the party, to the extent that the coffee makes you think that you are not intoxicated, it could also induce you to think you are sober enough to drive and put you at risk of a crash.

What about the effect of caffeine on other sedatives?

As it does when given with alcohol, caffeine may counteract some of the negative effects of various sedatives on alertness and some other tests of cognitive or motor functioning.

But people taking sedatives or anti-anxiety agents should consult their physician about ingesting caffeinated coffee or energy drinks, since such stimulants may impair the efficacy of the sedative or anti-anxiety agent.

In our guide for people with sleeping problems (available online at WorstPills.org) we explain how to avoid the need for using sleeping pills. In this guide we stress the need to avoid caffeine-containing beverages before going to sleep.

What You Can Do

Relatively little is known about the overall effects of combining energy drinks with alcohol. Patients are advised to avoid these combinations until more is known about their safety.

Do not assume that coffee or energy drinks will help you "sober up" or improve your driving ability if you have been drinking. They may make you feel less intoxicated, but that just increases the likelihood that you will take a chance and drive.