“How long does alcohol stay in your body?” is a pretty commonly asked question. Some people might be detoxing themselves from alcohol at home, have an upcoming alcohol test for a job, or may even be wondering how many hours to wait before they are able to drive again.
This is quite a detailed topic and there a lot of factors that come into play, including your size and weight, the type of alcohol you have consumed and more.
Roughly one drink per hour
The average healthy liver with no issues is able to process around one unit of alcohol per hour. This means that you can generally calculate the length of time alcohol stays in your system by dividing the amount you drunk into units and converting them into hours.
If you finish drinking a single unit by 7 pm, you should be clear by 8 pm. However, where people often get confused is the fact that these units add up, so if you have a second unit of alcohol at 7:30 pm, you now have both units in your system.
The original unit from 7 pm will have to be cleared before your kidney makes progress on the second one, so each drink increases your recovery time if consumed at a rate higher than one unit per hour.
Dr Paul Wallace, Chief Medical Adviser at DrinkAware says “The amount of alcohol in your bloodstream depends on three things. The amount you take in, over what period of time and the speed at which your body gets rid of it”.
There are some factors that affect how quickly you metabolise alcohol and whether you manage to rid yourself of more or less than that average of one unit per hour. These factors include:
- Stomach contents before drinking
- Liver health
How Long Does It Typically Take To Metabolize A Standard Drink?
Roughly one unit per hour is the easiest answer. However it’s definitely worth remembering that one unit isn’t necessarily one drink, so you can’t for example drink a pint of liquor then expect to be sober in an hour. 1 unit of alcohol is equal to around 10ml of pure alcohol.
Units Of Common Alcoholic Drinks
Here are the units of some common alcoholic drinks:
|Drink||Average Amount of Units|
|Standard (175ml) glass of average (12% alcohol) wine||2.1 units|
|A pint of strong (5.2% alcohol) lager or cider||3 units|
|A single measure (25ml) of spirits||1 unit|
|A pint of normal (3.6% alcohol) lager or cider||2 units|
Now it should be more clear why you don’t necessarily feel immediately fresh after 8 pints and 8 hours rest!
Average Time To Metabolise Common Drinks
|Type of alcoholic drink||Average time to metabolise|
|Shot of spirits||1 hour|
|Pint of regular lager||2 hours|
|Large glass of wine||3 hours|
This should also help you work out the answer to questions you may have about specific types of alcoholic drink, for example how long does beer stay in your system?
Some tips to help reduce the effects of alcohol and aid you in feeling better more quickly are:
- Drink more water – this helps reduce your Blood Alcohol Concentration (BAC) and helps alleviate the dehydration caused by alcohol
- Eat well – drinking on an empty stomach can exacerbate the symptoms as food in your stomach helps your body to absorb alcohol
- Avoid caffeine – caffeine dehydrates you just as much as alcohol and combining them can only make you feel worse
While the above can help you feel better, the average metabolization rate of 1 unit per hour will still apply, and unfortunately there is nothing you can do to directly increase the speed of this process.
How Long Does Alcohol Stay In Your Urine?
Urine tests look for alcohol metabolites, which are compounds created when alcohol is broken down by enzymes during the digestive process. These remain detectable in urine long after the alcohol has been processed and is no longer detectable in your blood.
Because of this, the average alcohol urine test can detect metabolites in your urine for 12 – 48 hours after drinking, and some more advanced urine tests can detect them for up to 80 hours.
How To Get Alcohol Out Of Your System For A Urine Test
Unfortunately, as mentioned above, there is no direct way to speed up your body’s metabolization of alcohol. Eating food, drinking water and of course avoiding any more alcohol can all help, but generally you will have to wait out the 1 unit per hour metabolization time before you can successfully get a “negative” for alcohol on a urine test.
There Are Two Main Forms Of Urine Tests For Alcohol
Ethanol Urine Tests
Once you start drinking, alcohol has to work its way through your digestive system before it begins to appear in your urine. Once it does show up, it will remain detectable for around 2 – 12 hours depending on how much you’ve drunk.
Ethyl Glucuronide Tests
Ethyl Glucuronide tests, also known as EtG tests, detect the presence of Ethyl Glucuronide, a substance that is naturally created by the liver as it metabolises alcohol. This is the more advanced test that can detect alcohol up to 80 hours after a person has consumed it, although in cases where extreme volumes have been consumed, it has been known to be effective for even longer.
While EtG tests are more accurate than any other urine tests, they are unable to be used for situations where the time of the drinking is important, for example for DUIs. This is because they can accurately tell you that somebody has alcohol in their blood and so has consumed alcohol in the last 80 hours, but it can not give any pointers as to when that actually occurred.
How Long Does Alcohol Stay On Your Breath?
That’s all good so far, but another common question for obvious reasons is “How long after drinking does alcohol show up on a breathalyzer?”
It does depend a lot on how much alcohol the person has consumed, and how long ago it happened but in general, with a healthy liver you can expect the BAC to reduce by around .015% per hour, which works out as roughly one drink.
This means if you have one drink you can likely drive safely after an hour, but if you have a BAC of 0.2%, it could take up to 13 hours before your breath is completely clear of alcohol.
Generally it is a good idea to keep this information in mind to help you figure out whether you’re safe to drive, but if there is any uncertainty whatsoever or any lingering feeling of intoxication, we recommend always erring on the side of caution.
If you find you are unable to keep enough time between drinking sessions to drive safely, or are often rearranging your life to make time for drinking, there is a chance you could be dependent on alcohol.
How Long Does Alcohol Stay In Your Hair Follicles?
Around 90 days! That might come as quite a surprise after how brief the effective time periods are for the other tests, but if you’re asking “how long does alcohol stay in your hair for testing”, the answer is around three months.
A hair follicle test detects EtG in the hair in a similar way to EtG urine testing, and will not point out when during this period the drinking took place, nor will it show up a positive result if you’ve only had one or two drinks.
Professional laboratories have a built in cut-off level that is intended to avoid false positives, so you need to have had a few drinks to get over that cut-off level. Due to the slow growth of hair, EtG also won’t show up in your hair for around 5 days after the date of drinking.
Hair alcohol tests are often used at rehab centres to confirm or disprove abstinence, allowing an educated and appropriate recovery plan to be devised.