How Our Body Processes Alcohol

The body is an amazing thing which can handle the right amount of alcohol efficiently if in a healthy state. But what happens when you overload the system with more than it can take? If you have drunk too much recently and it’s got you wondering ‘how long does alcohol stay in your blood’, this article is a must-read.

How long does alcohol stay in your blood

Our body processes alcohol depending largely on how many metabolizing enzymes you have in your liver. This will vary depending on the individual but in general, when you have one drink the alcohol concentration in your blood will peak at around 30-45 minutes.

As soon as the drink enters your system, 20% gets absorbed in the stomach and the remaining 80% gets processed in the small intestine. However, if the concentration of alcohol in your drink is higher, the quicker it will be absorbed in the body. This means that vodka (around 35-50%) will have a quicker absorption rate compared to beer (usually only 2-12%).

After the metabolizing process is complete the substance then passes onto the bloodstream and gets transported to the rest of the body. It then gets passed to the kidneys and lungs which remove the remaining alcohol through urination, respiration and perspiration.

Breathalyzer test for blood alcohol content.

This is why a breathalyzer test can be used as an accurate sign of your blood alcohol content. After this process has occurred the liver breaks down the final molecules and converts them into acetic acid.

When asking how long does alcohol stay in your blood for, it varies depending on the drink…

On average the liver takes an hour to process an ounce of alcohol. This will usually cause the average person’s blood to spike to a 0.015 level of blood alcohol concentration (BAC). Therefore, someone with a 0.015 BAC will have minimal or no traces of alcohol left in their blood after 10 hours has passed.

In other instances, for example when drinking a large glass of wine (250 ml), your body will take around 3 hours to process it. Whereas beer usually takes two hours to break down and a pint of larger (normally around 3 units) will take longer. So you need to be aware that if you do go out and have a few drinks, it can take several hours for the body to process and eliminate the alcohol. This means alcohol could still be found in your blood the following day.

Drinkaware’s Medical Adviser Dr Paul Wallace reminds us that “The amount of alcohol in your bloodstream depends on two things. The amount you take in, over what period of time and the speed at which your body gets rid of it.”

What’s BAC?

BAC, otherwise known as Blood Alcohol Concentration, relates to the amount of alcohol that gets absorbed by your body when drinking. The metabolizing process happens at around 0.015 BAC per 60 minutes. When your blood concentration reaches 0.05 or more, you will feel the negative side-effects of alcohol such as nausea, vomiting, memory loss and the dreaded hangover.

Blood alcohol concentration facts

Did you know? Hangovers area result the unprocessed toxins still left over in your system.

Interesting fact: As alcohol is a toxin, it stops the liver from metabolizing fat. Unlike fats, proteins and carbs, alcoholic molecules cannot get stored to be broken down later so they must be converted into carbon dioxide and water.

This table from Drink Fox is helpful when figuring out how quickly a beverage can exit your blood stream. You can tell how long it will take for your BAC to go back to 0.00 signaling all alcohol has left your blood:


Time BAC
2:00 0.16
3:00 0.144
4:00 0.128
5:00 0.112
6:00 0.096
7:00 0.08
8:00 0.064
9:00 0.048
10:00 0.032
11:00 0.016
12:00 0.000

So in the above example, this person will be below the legal limit by the next morning considering that started drinking at 2pm the prior day.

As there are so many varying factors that influence BAC, it’s hard to say how many beverages it would take for someone to reach the legal limit of 0.08%. On top of this, the amount of alcohol used for the same drink from bar to bar varies. Even though it’s hard to give a specific amount of time for the duration it stays in your blood, using this BAC calculator will give you a good estimation.

Since on average the body metabolizes alcohol at the rate of 0.016% hourly, it will take 10 hours in total until the blood alcohol content reaches 0 again.

Is there a way to reduce your BAC quicker?

The liver breaks down the alcohol on its own watch and little can be done to speed up the process. Even though people try drinking coffee, lots of water or eating high-fat foods it will barely influence the rate your body metabolizes alcoholic molecules.

Those who have been drinking heavily for years will have a higher alcohol metabolism than the average person. However, the downside is the potential for liver damage (cirrhosis) does increase. Once this disease arises, the enzymes such as alcohol dehydrogenase and CYP2E1 actually slow down when processing alcohol.

But when you want a more appealing answer to the question how long does alcohol stay in your blood, we can look at food you eat before drinking. Research has found that when the stomach is full, metabolism can increase by a small amount. Due to the increased blood flow to the liver and higher enzyme activity, the alcohol dehydrogenase activity temporary spikes.

Alcohol influences metabolism rate

It’s also good to remember the difference between absorption and metabolism when looking at alcohol blood levels. This is because metabolism remains steady at around 0.016% hourly but they way your body absorbs alcohol can change drastically.

Absorption rate will have a big effect over your BAC too and how quickly it peaks (the fall of BAC will be influenced by metabolism however). How effectively your body absorbs alcohol will depend largely on a number of individual factors such as gender, weight, body mass and how quickly you drink.

The general rule of thumb is the more you drink, the quicker your system absorbs it. Similarly BAC will peak quicker if you drink a certain number of drinks all together instead of over a few hours.

What happens to alcohol in the bloodstream?

Alcohol in bloodstream

Once you start drinking an alcoholic beverage, most of the substance enters your blood in a similar manner to food. After it’s in the bloodstream it gets transported to the brain where the feeling of drunkenness kicks in. Afterwards the intestines and liver slowly metabolize and break it down into non-toxic particles.

Alcohol also gets processed by the small blood vessels inside the stomach and small intestines. However when there is too much for the main metabolizing organs to handle, the leftover substance stays in the bloodstream and gets absorbed by the blood and tissues. This has a direct effect on how fast someone is drinking as the liver can only handle one ounce of alcohol per hour.

When you’re overloading your system and the BAC (blood alcohol concentration) rises above 0.55, this becomes dangerous. Once it’s in the bloodstream alcohol can enter into practically every biological tissue in your body as the cell walls are easily penetrable to the substance.

What factors affects the rate that alcohol leaves your blood?

As mentioned earlier, there are various factors that can affect how quickly alcohol is absorbed and eliminated by the bloodstream.

Here are some important elements affecting how quickly your BAC drops which then changes the answer to the question, how long does alcohol stay in your blood:

  • Gender

Men and women will naturally have different absorption rates as Brown University Health Education explains. This is because men have a higher water content of around 61% whilst women have around 52%. The higher water content means alcohol concentration will be diluted quicker and the less concentrated the blood becomes.

  • Food

High protein foods are always recommended before drinking alcoholic beverages. It will slow down the stomachs processing of alcohol meaning BAC will peak between 1-6 hours instead of 1-2 hours on an empty stomach.

  • How strong the drink is

The strength of your drink will also result in a higher BAC. This article published by the University of Notre Dame displays the alcoholic content of various drinks. The general rule is the higher content will irritate cell membranes and slow down absorption rates.

  • Your state of mind

Mood will also influence how someone reacts to drinking. For example, stressful states of mind such as depression, anxiety, stress and anger will alter stomach enzymes and how they react to alcohol.

Body type

People with less body mass will be more susceptible to the effects of alcohol. Also, if someone less body fat, it’s likely their BAC will be lower than those with a high percentage of fat.


The way medical drugs interact with alcohol differ but you still need to be careful as some meds, for example pain killers, can intensify the effects of alcohol as much as ten times!

Drinking when you’re ill

If you’re feeling under the weather, there’s a good chance you’re more at risk of the dehydrating effects of alcohol. When dehydrated, your liver becomes less efficient at getting rid of alcohol.

Need a helping hand?

If you’re struggling with the addictive effects of alcohol, you can release the pull it has on you with the residential and outpatient services offered at BLVD Treatment Centers. With full support and undivided attention of our experienced counselors, you can get access to:

  • Individualized Detox Treatments
  • Chef-Prepared Gourmet Meals
  • Medically-Assisted Detox
  • A Comprehensive Aftercare Plan
  • Convenient Transport Services

If you’re still unsure of whether you’re an alcoholic or not, try taking this quiz for a confidential answer. Either way, you’ll get the help and support you need at one of our centers located in: Hollywood, Portland, Orange County, San Diego, West Los Angeles, Give our team a call to see how we can help on 8885376671.