How Long Does Alcohol Stay in a Person’s Bloodstream

How long alcohol stays in a person’s bloodstream has a direct effect upon a person’s blood alcohol level (BAC).  (BAC) is determined by how quickly blood alcohol is absorbed, distributed, metabolized and/or excreted from the body. Studies show that once alcohol is ingested and enters the bloodstream, it leaves the body in two main ways: (1) breath, perspiration and urine; and (2) through the digestive process, i.e. metabolized by the liver.  There is some disagreement amongst experts regarding the factors to influence (BAC). For example some argue that the rate that alcohol is metabolized is almost identical regardless of a person’s height, weight, sex, race or other such characteristics. Others maintain that gender, race, food consumed with the alcohol, chronic alcohol consumption, drinking patters and/or medications all have a direct effect on one’s (BAC).

Nevertheless, most experts agree that Alcohol is metabolized at the rate of .015 of blood alcohol concentration (BAC) every hour.  Thus, a person with a very high BAC of .15 will have no measurable alcohol in the bloodstream after ten hours (.15 divided by .015 = 10). Here are some other examples:

BAC Level

Metabolism Time in Hours









It’s important to remember that BAC can continue to rise for a period of time after the last drink is consumed.  The affects of this trend can be illustrated through the Biphasic Curve.

There are several ways to control the rate at which your BAC rises. Here are some examples:

-Don’t be fooled. Standard drinks of beer, wine, or liquor (mixed drink or straight spirits) each contain virtually identical amounts of pure alcohol. When it comes to alcohol, a drinks are all the same to a breathalyzer.

-Eat food while you drink. Food, especially high protein food such as meat, cheese and peanuts, will help slow the absorption of alcohol into your body.

-Sip your drink. If you gulp a drink, you lose the pleasure of savoring its flavors and aromas.

-Don’t participate in “chugging” contests or other drinking games.

-Accept a drink only when you really want one. If someone tries to force a drink on you, ask for a non-alcohol beverage instead. If that doesn’t work, “lose” your drink by setting it down somewhere and leaving it.

-Skip a drink now and then. Having a non-alcoholic drink between alcoholic ones will help keep your blood alcohol content level down, as does spacing out your alcoholic drink.

-A good general guideline for most people is to limit consumption of alcohol beverages to one drink (beer, wine or spirits) per hour.

-Keep active; don’t just sit around and drink. If you stay active you tend to drink less and to be more aware of any effects alcohol may be having on you.

-Beware of unfamiliar drinks. Some drinks, such as zombies and other fruit drinks, can be deceiving as the alcohol content is not detectable. Therefore, it is difficult to space them properly.

-Use alcohol carefully in connection with pharmaceuticals. Ask your physician or pharmacist about any precautions or prohibitions and follow any advice received.

Although we can control how high our BAC goes, we can’t speed up our metabolism of alcohol. Drinking coffee, exercising or taking showers and similar behaviors have no effect on alcohol metabolism. Only time can do that.

You may not know it, but the human body produces alcohol around the clock naturally. It’s called “endogenous ethanol production” and the volume of alcohol produced depends to some degree on what foods have been eaten. On average, it appears that people can produce about one ounce of absolute or pure alcohol each day.  However, the law doesn’t distinguish between alcohol produced in the body and that which is consumed.

Unfortunately, so-called alcohol breath testing machines only estimate BAC, which can only be measured by testing the blood itself. Breath, perspiration and urine can only be tested to estimate the amount of alcohol in the bloodstream.

Research indicates that a large proportion of people tested with a Breathalyzer or similar breath machine will receive a reading higher than their actual BAC. This means that many innocent drivers are falsely convicted of DWI/DUI.

But there is good news. You can easily avoid both alcohol-impaired driving and unfair DWI/DUI convictions by abstaining, drinking in moderation, or either being or using a designated driver (DD) who consumes no alcohol.

**This article is for informational purposes and is not intended to serve as a summary of medical or scientific studies.  For answers to specific health questions always consult your primary care physician and/or a competent medical professional.**

For more detailed information on blood alcohol content see: “How to Control Your Drinking” by William R. Miller and Richard F. Munoz and “How Alcohol Effects Us: The Biphasic Curve” by David J. Hanson, Ph.D.

Rouse & Co., LLC Attorneys at Law is an established DUI and Criminal Defense Law firm that serves clients in Atlanta, Georgia as well as Snellville, Loganville, Lawrenceville, Lilburn, Suwanee, Duluth, Norcross, Buford, Monroe, Conyers, Convington, Stockbridge, Riverdale, Jonesboro, Fayetteville, Douglasville, Decatur, Doraville, Tucker, Fairburn, College Park, East Point, Peachtree City, Midtown Atlanta, North Atlanta, Buckhead, Marietta, Forest Park, Smyrna, Vinings, Mableton, Union City, Roswell, and Sandy Springs; we serve communities in a variety of counties including but not limited to: Gwinnett County, DeKalb County, Clayton County, Henry County, Newton County, Rockdale County, Walton County, Fayette County, Fulton County, Douglas County, and Cobb County. Call us for immediate legal help at reasonable, fair, and inexpensive prices, cost, and/or fees. 
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