Last Updated on March 14, 2025
It’s widely known that NyQuil and other cold medicines like Robitussin or Vicks Formula 44 contain alcohol, so people often wonder if they risk getting a DUI just for driving with a cold or flu. It’s a fair question, especially considering that having a fever can increase your BAC up to 9%. So, will NyQuil show up on a breathalyzer? In general, it’s best to avoid driving on cold medicine. Here’s why.
Table of Contents
How Much Alcohol is in NyQuil?
NyQuil and ZzzQuil contain 10% alcohol (making these as strong as wine). A few cold medications even have 20% alcohol (as much as many flavored liquors). While this makes them just as strong as many alcoholic drinks, remember that a medication dosage is smaller than a typical shot, meaning the small amount of alcohol in these medications should not be enough to leave you intoxicated.
Notably, DayQuil, NyQuil LiquiCaps, and Alcohol-Free NyQuil do not contain any alcohol.
How Much NyQuil Will Make You Fail a Breathalyzer?
The good news is that using the recommended amount of NyQuil, ZzzQuil, or other cold medicines should not put most people over the legal limit to drive. The majority of drivers would need to drink at least 10 ounces of NyQuil (the equivalent of nearly 20 doses and almost an entire bottle) to get a BAC above the legal driving limit. Even commercial drivers and on-duty ride-share drivers would need to take about ten doses of the cold medicine before they would fail the breathalyzer.
However, the legal limit for those under 21 is 0.01%, so if you are under the legal drinking age, it’s best to avoid using any cold medication that contains alcohol because NyQuil can easily make you fail a breathalyzer test.
Can You Get a DUI for Driving on NyQuil if You’re Over 21?
Unfortunately, for sick people hoping to get relief from cold medicines before they hit the road, it doesn’t take a whole bottle of the medication to fail a breathalyzer. Many people who are ill avoid eating and have a fever, both of which can make your BAC falsely high when you take a breathalyzer. So if the only thing you have in your stomach is NyQuil and a breathalyzer test is administered, even an adult could fail it, especially if they are petite. In other words, if you’re sick, don’t assume you’re under the legal limit just because you haven’t consumed an entire bottle of Nyquil because simply having a fever or failing to eat could increase your BAC.
Beyond that, the active ingredients in NyQuil ensure it’s still not considered safe to drive on the cold medicine, even if your BAC is still below the legal limit. If a police officer believes any substance, including an over-the-counter medication, negatively impaired your driving ability, you can still get a DUI. In many cases, these charges can be reduced to a wet reckless charge. However, it is still best to avoid driving after drinking NyQuil or other cold medication, especially one designed to induce drowsiness.
How Long After Using NyQuil Can You Drive?
This question has a few answers, depending on how you view it. If you ask, “how long does NyQuil stay in your system,” the effects should wear off after about five hours.
On the other hand, some people wonder how long they should wait before driving after immediately taking the medication because it contains alcohol, which means you may have alcohol in your mouth if asked to take a breathalyzer. Sometimes, alcohol in the mouth can cause breathalyzers to have artificially high results. This problem occurs more frequently with less-sensitive, less-accurate Portable Alcohol Screening (PAS) devices, which are often administered within 15 minutes of the initial traffic stop when someone could still potentially have medication remaining in their mouth or esophagus.
The only people legally required to take these PAS tests are minors, and everyone else is advised to refuse to take these tests and instead insist on taking only a real breathalyzer. Before administering the official breath test, an officer must monitor a suspect for 15 minutes to ensure they do not belch, burp, vomit, or do any other action that allows alcohol from the stomach to re-enter the mouth or esophagus.
If you think the amount of time between when you took NyQuil and took the breathalyzer was less than 15 minutes or if the officer that arrested you did not watch you for 15 minutes before administering the breath test, mention this information to your DUI lawyer because it could provide him with a valid reason to challenge the results of your breath test.
Will NyQuil Show Up on Ignition Interlock Devices?
Another thing to remember about NyQuil use while driving is that many drivers with prior DUIs must install an ignition interlock device (IID) that requires them to submit a breath sample every time their vehicle is started. Because those on probation will have their IID set to 0.029%, it is possible to go over this limit by drinking nothing more than cold medicine, especially if you have a fever or took the medication on an empty stomach shortly before driving.
Since IIDs are used as part of a probation agreement in which you most likely agreed not to drink at all, failing a test on this device could violate your probation. While your probation defense attorney can help you fight against additional penalties, the probation officer will usually argue that you should have known the medication contained alcohol and violated your probation by drinking it before driving.
While serving on probation, it’s best to avoid using cold medications that contain alcohol, but if you make a mistake, always contact a defense lawyer to help represent you at your probation hearing.
If you have been accused of driving under the influence of alcohol after taking a cold medication, such as NyQuil, please call (760) 643-4050 to schedule a free initial consultation with Peter M. Liss.
