How long alcohol remains in your system after you drink depends on several factors. How much alcohol you consume, how often you drink, and how your liver handles the substance are the main determinants.
Factors That Affect Alcohol in Your System
Alcohol is absorbed, metabolized, and eliminated at a different rate in each person. The following information describes the main factors that affect how long alcohol will be detectable in your system after you take a drink or two.
The Alcohol Content
The alcohol content, which in turn depends on the type of drink, is one of the main factors that determine how quickly your body processes your drink.
According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), one standard drink contains about 0.6 fluid ounces or 14 grams of "pure alcohol" and is equivalent to the following:
- One can or a 12-ounce glass of beer
- Five ounces of wine
- One shot (1.5 fluid ounces) of 80 proof liquor (40 percent alcohol) such as whiskey
Be mindful that the alcohol content will be higher if the volume of your drink is bigger than one standard, which is often the case. For example:
- A typical glass of wine most people consume contains about two to three standard drinks.
- A serving of draft beer might be equivalent to two or three drinks, as well.
- A mixed cocktail might contain more than one shot of hard liquor.
These drinks will take more time to get out of your system.
How Fast You Drink
In addition to how many drinks you consume, how fast you drink them also determines how high your blood alcohol level rises and how long alcohol lingers in your system. Your liver can metabolize only about one drink per hour, according to info from Brown University. If you have three standard drinks in one hour, it will take your liver around three hours to metabolize them, no matter which type of drink. Note the following underlying facts:
- Alcohol metabolism by the liver is slower than its absorption from the gut into your bloodstream.
- Therefore, if you have two or more standard drinks in quick succession in a drinking session, it takes longer for your liver to keep up and metabolize the alcohol load and excrete it.
- This causes alcohol to build up in your blood and stay longer in your body and on your breath.
- Even after your last drink, your blood alcohol concentration (BAC) may still continue to rise as the remaining alcohol is absorbed from your gut into your blood over time.
How Often You Drink
If you drink many times in a day or a week, it will also take longer to clear the alcohol from your system. In this situation, the liver is under an almost constant state of bombardment and can't metabolize the alcohol fast enough. This habit can lead to alcohol dependence and alcohol addiction.
Frequent drinking and binge drinking sessions can a lead to a greater risk of accumulation of high levels of alcohol in your blood, brain, and other tissues. This can lead to alcohol intoxication, overdose, and alcohol poisoning, with the risk of brain damage and death.
The Rate of Your Liver Metabolism
Alcohol metabolism occurs by specific enzymes in the liver which eliminates the by-products in bile and urine. Alcohol is also cleared from the blood through the lungs and sweat.
The rate of at which the enzymes work helps to determine how fast you get rid of alcohol from your system. The following factors can affect how fast each person's liver metabolizes and excretes alcohol.
- Gender: Women metabolize alcohol slower than men; therefore, it will linger longer in their blood. Women will have a higher blood level than men for the same amount of alcohol they drink.
- Age: Liver metabolism can slow with age; therefore, the older you are the slower the alcohol will be eliminated from your blood and body.
- Weight: It is possible that some people who are thin might have a faster metabolism than those who are heavier and therefore tend to get rid of alcohol faster.
- Body fat: Alcohol dissolves in water but not in body fat. The more body fat compared to lean muscle you have, the higher your blood alcohol level reaches and the longer it takes to metabolize it.
- Food intake: Food in your stomach can delay alcohol absorption into your blood and your liver. The more fat in the meal, the slower the absorption and metabolism of alcohol.
- Liver disease: Hepatitis and other diseases can impair how the liver processes alcohol and slow its elimination from the body.
- Genetics: This influences the activity of the liver enzymes that metabolize alcohol and therefore how quickly blood alcohol level decreases.
You Can't Speed up Alcohol Metabolism
There really isn't anything you can do to speed up your metabolism of alcohol. Some people suggest drinking a lot of water or exercising and sweating can flush out alcohol quicker from your system. However, those actions are not effective. Drinking coffee will also not increase how fast your liver metabolizes your drinks or decrease your blood alcohol content.
Detecting Alcohol in Your System
Alcohol in your system can be measured by a breathalyzer or a blood test. Your blood alcohol content (BAC) can go to zero within three hours if you have only one standard drink. If you have more than one drink, especially back-to back, your blood level will rise higher and take longer to be undetectable.
The following chart gives you an idea of how long it can take your BAC to fall to zero after fast consumption of specific numbers of drinks. It is based on information from a graph in a National Institute on Alcohol Abuse and Alcoholism article.
| Number of Drinks | Time to Zero BAC |
|---|---|
| 1 | 3 hours |
| 2 | 4 and 1/2 hours |
| 3 | 6 hours |
| 4 | 7 hours |
The times can vary depending on the factors discussed above.
Keep These Times in Mind
Keep these elimination times in mind if you decide to get on the road and drive soon after your last drink. Your blood alcohol level might still be elevated, and you can still have alcohol on your breath. You are likely to fail a breathalyzer or a blood test if you are compelled to do either test if you get caught on the road within three hours after your last drink.
Legal Alcohol Limit
Often at a bar happy hour other social gatherings, or during binge drinking episodes, people can lose track of the pace of their drinking. In the USA, you can legally drive before your BAC reaches zero because the legal limit for driving is 0.08 percent or 80 mg/deciliter (dL), according to a graphic in another NIAAA article.
Note, however, that signs and symptoms of alcohol brain impairment, such as poor perception, coordination, and driving skills can still be present at a BAC of 0.05 percent to 0.06 percent (50 to 60 mg/dL) or even if your BAC is undetectable. It is not safe to drive if you are still feeling foggy-headed and your judgement is impaired.
Manage Your Alcohol Consumption
After you have a drink or two, it takes some time for the alcohol to clear from your system. The time-frame depends on several factors. Your knowledge of these factors can help you understand how to manage your consumption of alcohol safely.
