How long does it take for alcohol to reach the brain?

In this post we are going to answer the question ‘’How long does it take for alcohol to reach the brain?’’ We will discover the effects of alcohol on the nervous system and how long it takes for these effects to reach the brain.

How long does it take for alcohol to reach the brain?

Alcohol takes six minutes to reach the brain. 

Alcohol goes to the head. Researchers at the University of Heidelberg (Germany) have verified how quickly it does this and have concluded that only six minutes after drinking an amount of alcohol equivalent to three glasses of beer or two glasses of wine – which is a blood alcohol level of 0.5 or 0.6- and changes occur in brain cells.

They have observed this through the use of magnetic resonance spectroscopy. The data available so far came exclusively from animal tests.

The results, which are published in the Journal of Cerebral Blood Flow and Metabolism, say that the brain reacts quickly to alcohol. «Our study provides evidence of the use of alternative energy in relation to the ingestion of alcohol.

For example, the brain uses a derivative of alcohol instead of glucose for its energy needs, ‘explains Dr Armin Biller, from the Department of Neuroradiology in Heidelberg. In this way the harmful effect occurs quickly.

During the experiment, the concentration of substances such as creatine, which is related to the protection of cells, is reduced as the concentration of alcohol increases.

Choline, a component of the cell membrane, is also reduced. “This probably indicates that alcohol induces changes in the composition of cell membranes,” said Dr. Biller.

Just as the effect of alcohol comes quickly, it also usually disappears without leaving sequelae. “Our follow-up showed the next day that changes in brain metabolites after moderate alcohol consumption in healthy people were completely reversible,” said the expert.

However, “the brain’s ability to recover from the effect of alcohol decreases or is neutralized as alcohol consumption increases. The acute effects showed in our study that they could possibly form the basis for permanent brain damage that occurs in alcoholics “, a point that” should be clarified in future studies. “

How is alcohol metabolized?

Although alcohol passes through the digestive system, it does not undergo extensive digestion within the digestive tract in the same way that food does.

When it reaches the upper gastrointestinal tract, a significant portion is absorbed directly into the bloodstream through the tissue lining of the stomach and small intestine. Once in the bloodstream, it is transported throughout the body and travels to the brain.

The absorption process can be somewhat slower when there is food in the stomach. 

Food can absorb alcohol, prevent it from coming into contact with the stomach lining, or delay its transit from the stomach into the duodenum (the first portion of the small intestine), where it is otherwise absorbed very quickly into the bloodstream.

How long does it take to trigger alcohol?

In 15 to 45 minutes, a healthy person can usually experience the effects of a drink.

When their blood alcohol content (BAC) exceeds 0.05 percent, most men with little to no tolerance will begin to show certain signs of intoxication and their ability to drive will be substantially affected at 0.07 percent. The Y would be obviously intoxicated at 0.10 percent.

If she consumes about 4 drinks per hour, a woman who weighs 150 pounds can reach a BAC of 0.1 percent (intoxication)

How does alcohol advance in the brain?

Just two glasses of wine and a can of beer are enough for a person to be intoxicated. With this amount of alcohol, which may seem inconsequential to many, peripheral vision is reduced, reaction time decreases from 30 to 50% and imbalance begins to prevail.

On the eve of National Holidays, the inns, the asados ​​and the multiple social gatherings to celebrate the country, considerably increase the consumption of wine, beer and other typical drinks of the date.

Alcohol interferes with the biological processes of neurotransmitters that a person needs to react, process, move, look and think.

In fact, it only takes five minutes from the start of drinking alcohol for the body to absorb some of this substance. In this first stage, a feeling of euphoria is generated, during which people are not aware of the consequences that drinking has on the brain and its functions.

Alcohol acts as an anesthetic that depresses the Central Nervous System and, as consumption increases, the effects are exponential, generating from one minute to the next, motor slowness and mental processing.

What really happens in the brain?

To visualize this process, the neurologist makes the following comparison, taking as an example a man of approximately 80 kg and using two typical drinks throughout the year and especially at this time.

2 glasses of wine (200 cc each)

At this time, the person is already under the influence of alcohol and has 0.5 grams of alcohol per liter of blood. He has lost about 15% of his visual performance and his hearing is affected as well.

With these senses compromised, he is no longer able to correctly estimate speed and can, for example, and is more susceptible to accident or become the protagonist of an incident.

This individual believes that he is being careful when in reality he is more fearful and the brain is no longer functioning properly.

2 glasses of wine + a can of beer

This amount of drinks translates into 0.8 grams of alcohol per liter in the blood and the patient is already intoxicated.

At this stage the vision becomes peripheral, which is why the objects approaching from the sides are no longer perceived. The reaction time decreases from 30 to 50% and the body begins to fight against imbalances.

1 bottle of wine (750 cc)

In the so-called stage of intoxication, the subject has 1 gram of alcohol per liter of blood and there are clear disorders in speech, reaction capacity, balance and orientation.

The drink is metabolized mainly in the liver, but also in the kidneys and the skin, so that drunkenness is completely evident for the environment of the person, both by its way of acting and by the smell it emanates.

Effects of alcohol on the nervous system

Frequently, adults and the occasional young person, we consume alcohol in convivial events, or simply to taste a “glass” of red wine. It is well known that alcohol disinhibits the shyness of people allowing their interaction with their companions, generating a state of well-being or relaxation.

But have you ever wondered how this is possible? What are the effects of alcohol on our body? Is there a risk to my body if I drink frequently or occasionally?

In our body, there are biomolecules called neurotransmitters, these are responsible for stimulating our brain to alert us to a dangerous situation, or allow the generation of feelings of pleasure, pain or sadness.

Two of these neurotransmitters are responsible for numbing our nervous system: gamma-amino butyric acid (GABA) and glutamate.

When we consume a few extra “cups”, the activity of these neurotransmitters is stimulated creating a state of relaxation and numbness, our reflexes become more clumsy and we tend to lose our balance easily, but why at the same time do we feel pleasure or wellness?

Alcohol acts on two other neurotransmitters responsible for feelings of pleasure and euphoria: dopamine and serotonin.

Alcohol affects our behavior and mood. So is it good to consume alcohol regularly?

The answer to this question is somewhat controversial since among several factors is the amount we drink and it leads us to this other question: What is the maximum amount we can consume? The limit doses vary in each country, but we are sure that there are limits and risks of alcohol consumption.

The World Health Organization (WHO) recommends a daily limit of 3 units for men and 2 units for women. But what is a unit? How many units does a beer contain?

We give you this example: one unit equals 8 grams of pure alcohol; a 330 mL beer with a 5 ° graduation (degrees) contains 13 grams of alcohol (1.6 units); and a 100 mL wine glass with 12 ° contains 9.6 grams of alcohol (1.2 units).

In such a way that, according to the WHO, men and women should consume a limit of 1.8 and 1.3 beers a day respectively.

Final words

All alcoholic beverages contain a molecule that affects brain function and is responsible for drunkenness: ethanol. 

This substance has a very low molecular weight, which allows it to cross the membrane of the small intestine and the mucosa of the stomach in record time: it only takes 30 to 90 minutes after we consume alcohol for us to reach the maximum state of intoxication.

When ethanol enters our body, it passes into the bloodstream and from there it reaches the brain. This molecule has the ability to slow down the functioning of our brain due to the binding with two types of receptors: γ-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA).

GABA neurotransmitters inhibit our behavior, and what happens when they bind with ethanol is that the neural message slows down, allowing us to feel calmer and more relaxed.

On the other hand, when alcohol molecules bind to NMDA receptors, we feel more tired and it can interfere with our memory. Therefore, the more ethanol we have in the body, the less we will remember, which can cause memory gaps to occur.

At the same time, when we consume alcohol, the brain releases norepinephrine, adrenaline and cortisol, which are stimulating substances that increase our heart rate. The airways open and send more oxygen to the brain, increasing the sensations of the senses. Dopamine, the happiness neurotransmitter that makes us feel good, is also produced.

Additionally, ethanol binds to the pathways through which the brain receives energy, affecting thought processes and our ability to make decisions.

But alcohol not only affects our mental processes, it also has consequences for the rest of the body.

It inhibits the antidiuretic hormone, which forces us to urinate more frequently and consume more fluids to stay hydrated. Muscle movement is also affected, making us clumsier and slower, and can interfere with circulation, breathing, and the regulation of body temperature.

As you have seen, drunkenness triggers a chemical pump in our brain and affects many functions of our body, so it is recommended that you drink in moderation.

FAQS: How long does it take for alcohol to reach the brain?

How quickly can alcohol reach your brain if you drink on an empty stomach?

If we drink alcohol on an empty stomach, or with small amounts of food, the alcohol quickly passes the pylorus and will be absorbed quickly. In 5 minutes we already have alcohol in our blood. At 30-45 minutes we reached our highest BAC.

Does the brain repair itself from alcohol?

People in recovery should rest assured that certain brain functions can completely recover, according to a recent report on recovery of behavior and brain function following alcohol abstinence, while others can require further effort.

How long does it take to get 0 after drinking?

The liver is only capable of metabolizing 0.12 g / l of alcohol in the blood every hour, with which the elimination process (depending on the alcohol consumed) could end up to 19 hours later.

Does alcohol speed up the brain?

Excessive alcohol consumption can increase the risk of a stroke (which causes brain damage due to a blood clot), cancer, liver disease, and other diseases.

How long does being drunk last?

There is talk of drunkenness when we are under the influence of excessive alcohol consumption. 

Therefore, although there are some factors that determine the greater or lesser effect that alcohol produces on our body, we cannot speak of drunkenness due to the effect that drinking a beer or glass of wine causes us.

In this post we answered the question ‘’How long does it take for alcohol to reach the brain?’’ We will discover the effects of alcohol on the nervous system and how long it takes for these effects to reach the brain.


Ewing, JA (October 1984). “Detecting alcoholism. The CAGE questionnaire”. JAMA: The Journal of the American Medical Association. 252 (14): pp. 1905 – 1907.