In This Article
How Does the Body Metabolize Alcohol?
Alcohol metabolism is the process through which the body breaks down and eliminates ethanol. In general, alcohol metabolism occurs via both oxidative and nonoxidative pathways.1 The liver is the main organ involved in the process, metabolizing up to 90 percent of the alcohol content in the body.
The main enzymes involved in alcohol metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). During the process, ADH is oxidized to acetaldehyde in the presence of cofactors. However, since ADH is highly toxic and reactive, it's further oxidized into acetate, which is harmless.
Other enzymes involved in alcohol metabolism include cytochrome P450 2E1 (CYP2E1) and catalase.2 However, CYP2E1 is only active when a significant quantity of alcohol has been consumed. Catalase, on the other hand, only metabolizes a tiny portion of the alcohol in the bloodstream.
How Long Does Alcohol Stay in Your System?
Alcohol is detectable in your body for hours, days, weeks, or even months, depending on your ability to metabolize alcohol, the test used, and the type of alcohol consumed. Ideally, a small shot of liquor will be processed in one hour, whereas a few drinks may take several hours. Below are alcohol detection timelines based on the type of body system:
- Blood: Up to 6 to 12 hours
- Breath: 12 to 24 hours
- Urine: 12 to 24 hours or more if with advanced methods such as Ethyl Glucuronide (EtG)
- Saliva: 12-24 hours
- Hair: Up to 3 months (90 days)
Only about 0.7 to 1.5 percent of the alcohol consumed by a moderate drinker is excreted in the urine. Within an hour after drinking, the ethanol in alcohol may be detected in a person's urine using a urine test. This is usually the case for up to 6 to 12 hours after consuming alcohol. This period may change depending on a variety of factors, including the type of test used.
The Urine Ethyl Glucuronide (EtG) test is a standard urine test that may detect recent alcohol use even if no measurable alcohol is present in the system.3 EtG is a direct alcohol metabolite that appears in the urine shortly after alcohol intake.
However, according to the Substance Abuse and Mental Health Services Administration (SAMHSA), EtG tests are not always accurate and may produce a "false positive" result. In addition, urine tests are often not performed at the moment of an incident, such as a traffic stop, because sample results may be influenced by time.
Urine testing may also confirm abstinence and identify relapse in those legally banned from consuming alcohol by the court system or by their employer.
Alcohol breath tests can detect alcohol consumed within the last 12 to 24 hours, on average, by analyzing the air you breathe out. The test is done by a small gadget known as a breathalyzer which measures the blood alcohol content (BAC) — you blow into it, and it immediately gives a reading.
The BAC limit for adults was set at 0.08 percent because the National Highway Traffic Safety Administration (NHTSA) funded numerous research on impaired driving and discovered that at that level, nearly all driving-related abilities are significantly impaired.4
In this case, anything above 0.08 percent is considered high and unsafe for operating machinery or carrying out safety-based tasks.
Police employ breath tests during traffic stops to determine how much alcohol is present in a suspected person's blood. They are much simpler, accurate, and safer compared to urine tests.
In the United States, all states have "zero tolerance" rules for drivers under 21. Juvenile drivers are prohibited from driving with any detectable amount of alcohol in their system.
The most accurate way of detecting alcohol intake is by examining the EtG (Ethyl Glucuronide) and fatty acid ethyl esters (FAEEs) markers in your hair.5 Both EtG and FAEE are direct alcohol consumption indicators generated after a person has drunk alcohol or has high BAC levels. They get into the hair strands via sweat and diffusion and usually affect the entire strand.
Typically, the hair alcohol test is ordered during DUI cases, parental custody disputes, clinical treatments, and underage drinking investigations. In addition, this alcohol test may be used in conjunction with a hair follicle drug test to test for both drugs and alcohol. The test can detect alcohol consumption for up to 90 days.
To ensure the accuracy of results, hair alcohol tests must be carefully analyzed, especially for patients using chemical treatments for their hair. This is because research has shown that the presence of alcohol-containing hair products may lead to contradictory results.6 In this case, all these factors must be assessed before computing the final results.
Factors That Affect Blood Alcohol Concentration (BAC)
Below are factors that affect blood alcohol concentration (BAC) in the body.7
Rate of Metabolism
The rate of metabolism differs from person to person. An individual with a higher rate of alcohol metabolism will have a lower BAC level than one with a lower metabolism rate even after taking equal amounts of alcohol.
In addition, the body absorbs alcohol faster than it breaks it down. This means that the quicker you consume alcohol, the less time you give your body to break down alcohol.
Women usually get drunk more quickly than men. This is because alcohol dehydrogenase (ADH), the enzyme that metabolizes alcohol, is lower in women than men (men have 40 percent more). The consequence of this is that alcohol will stay longer in a woman’s blood, increasing the chances of quick intoxication as more alcohol is consumed.
Women also have a greater body fat percentage, which lowers the proportion of lean body mass that can disperse alcohol concentrations.
A woman's BAC is also likely to be greater shortly before menstruation than at any other time.
The more weight you carry, the more water you accumulate in your body. Because water dilutes the alcohol and may decrease a person's BAC level, a person who weighs more will have a lower BAC level after drinking the same quantity of alcohol than a person who weighs less.
The faster someone drinks, the faster their peak blood alcohol concentration rises, and the faster they get drunk. This is because the liver is built to only handle one standard drink each hour. When that pace is exceeded, more alcohol enters the bloodstream, causing a person to get drunk more quickly.
By holding the alcohol in your stomach for a longer period of time, food helps to delay the absorption of alcohol into your blood, thus affecting the BAC. This is why individuals who drink on an empty stomach will notice the effects of alcohol more quickly.
Alcohol has a diuretic effect, meaning it inhibits water absorption into the bloodstream while enhancing elimination through urine. Research indicates that consuming 250 ml of alcohol can cause the body to expel up to 1000 ml of water, resulting in increased BAC levels.7
Presence of Carbonates
Carbonation speeds up absorption. Alcohol mixed with carbonated beverages such as Coca-Cola or tonic water will be absorbed more quickly into the bloodstream, thus affecting BAC levels.
When people are stressed or tired, alcohol has a stronger impact than usual. When you're anxious, your body diverts blood away from your stomach and into your muscles, slowing absorption. When you relax and your blood begins to flow properly again, your BAC may rise.
How Long Does it Take to Feel Alcohol’s Effects?
Alcohol enters your system as soon as you take that first drink. The first effects of alcohol set in fairly quickly, even if you don't notice them right away.
According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), the effects are noticeable within 10 minutes and hit their peak after about 30 to 45 minutes.8 However, the strength may vary from person to person due to the factors discussed in the previous section.
For example, if you have food in your stomach, alcohol absorption will be hindered, thus slowing the onset of the effects.
How Does The Body Eliminate Alcohol?
When ethanol enters the bloodstream, it travels to all bodily tissues, including the brain, causing intoxication. Our bodies are built to halt the effects of substances like alcohol, so that effects do not last after a person stops drinking. In fact, the body begins to eliminate ethanol even before it enters the bloodstream.
The rate at which alcohol is eliminated from the blood is about 3.3 mmol/hour (15 mg/100 ml/hour), although this varies across individuals, drinking occasions, and the quantity of alcohol consumed.
Ideally, more than 90 percent of alcohol is excreted through the liver. 2 to 5 percent is excreted unchanged in urine, sweat, or breath.9
Oxidation by alcohol dehydrogenase is the initial step in metabolism and elimination. In this case, ADH converts alcohol to acetaldehyde, a very toxic substance that is also a recognized carcinogen.
Subsequently, in the second stage, aldehyde dehydrogenase (ALDH) breaks down acetaldehyde into acetate. Acetate is a less active byproduct, which is further broken down into water and carbon dioxide for easy elimination.
Alcohol is also eliminated in small quantities by reacting with fatty acids to produce fatty acid ethyl esters (FAEEs). These chemicals have been linked to liver and pancreatic damage. However, they're markers of ethanol levels in blood and tissues, thus useful in identifying chronic alcoholism.
How Long Does it Take for the Effects of Alcohol to Wear Off?
Before you get to know how long it takes for the effects of alcohol to wear off, it's important to know what effects alcohol elicits in the first place. Most people consider themselves drunk when they experience the following:
- Impaired judgment
- Muscle incoordination
- Trouble concentrating
- Slurred speech
It's not easy to predict how long these effects may last. Factors such as age, weight, amount consumed, gender, stomach contents, health status, and overall tolerance to alcohol will determine how fast or how slow the effects wear off.
Although there is nothing you can do to speed up sobriety after getting drunk on alcohol, there are a few things you can do to shake off some of the effects. These include:
- Hydrating: Water and other nonalcoholic drinks will not help you get the alcohol out of your system quicker, but they will help you feel less lethargic and prevent a bad hangover. Even better, begin hydrating before you have your first alcoholic beverage.
- Drinking coffee: Caffeine counteracts the "unwanted" effects of alcohol by inhibiting the adenosine A1 receptors that mediate the somnogenic and ataxic effects of alcohol after acute consumption.10
- Exercise: Although research has not entirely proven that exercise enhances the rate at which the body processes alcohol, physical activity can increase alertness and generate energy to counter the adverse effects of alcohol poisoning or intoxication, such as trouble concentrating and nausea.
- Taking a nap: Your body needs time to eliminate alcohol metabolites. Taking a nap will allow time for the effects of alcohol intoxication to wear off.
Are You at Risk of Alcohol Use Disorder?
When you can't manage how much you drink and have difficulty controlling your emotions when you aren't drinking, physicians call it alcohol use disorder or AUD. Although alcohol use disorder (AUD) is prevalent among individuals in their 20s and 30s, it can catch up with you at any age. Below are the risk factors of AUD:
- Regular consumption: Drinking alcohol every day/binge drinking may lead to dependence.
- Starting at an early age: People who start drinking early in life increase their risk of developing AUD.
- History of trauma: Emotional or other types of trauma can greatly influence drinking habits, leading to AUD.
- Mental health issues: People with mental issues such as anxiety, bipolar disorder, or depression often have issues with alcohol and drug use, increasing the risk of AUD.
- Social and cultural factors: The influence of friends, peers, parents, and social media can enhance the risk of AUD.
Treatment for Alcohol Misuse & Addiction
There are various treatment options for people with alcohol use disorder - all focused on addressing the patient's specific issue. In most cases, a combination of treatments and programs may be much more beneficial.
In general, you can seek outpatient or inpatient therapy, partake in additional medications, or join a support group.
Inpatient: If you've been severely misusing alcohol, this may be the best option for you. You commit to staying in a clinic, hospital, or detox facility full-time. During your treatment process, you'll have access to assistance 24 hours a day, seven days a week.
Outpatient: If you choose this option, you'll have the flexibility of undergoing addiction therapy while tending to your other responsibilities. This option is recommended for people with mild to moderate alcohol addiction.
Counseling: A therapist may come in handy during the recovery process. Social workers, counselors, and psychologists can educate you on how to deal with stress, avoid behavior that influences alcohol use, and how to build a strong support mechanism to support your sobriety.
Medication: Antabuse (Disulfiram), Campral (Acamprosate), and Naltrexone (Revia) are the three FDA-approved relapse prevention medications. These medications are scientifically proven to be effective, and they may be taken alone or in conjunction with therapy.
Support groups: These are groupings of individuals who suffer from alcoholism. Alcoholics Anonymous (AA), and SMART Recovery, are examples of such. Your peers can help you stay accountable by providing understanding, support, and guidance for years.