You are out drinking with a friend when the night begins to wrap up. You realize it is time to drive home, but you can tell that you are still a bit intoxicated. You are not sure if you should drive, both because you do not know if you can do so safely and because you may be arrested on drunk driving charges.
Your friend tells you that there is a simple fix. They feel the same way as you, but they say that both of you can quickly sober up if you just go to a nearby coffee shop, buy a large cup of black coffee, and drink it relatively quickly. Is this a good way to reduce your blood alcohol concentration (BAC) and drive home safely?
Your BAC will be the same
No, in this hypothetical example, your friend is simply telling you a common myth about alcohol impairment. Many people do believe that drinking coffee can help, but the truth is that it does not lower your BAC. The only thing that actually causes your BAC to go down is time, and it drops at a rate of about 0.015% every hour.
To some degree, then, going to get coffee can help because it takes time. Your BAC will slightly decline if it takes you an hour to go to the coffee shop, drink your coffee and then return to your car. Additionally, the caffeine can make you feel a bit more awake, which you may mistake for being sober at the end of the night.
But the truth is that your BAC is almost the same, so you could still face drunk driving charges. If you do, you need to begin looking into your defense options.