Alcohol is mainly broken down by the liver, which can metabolize 1 standard drink per hour for men. Factors such as age, weight, gender, and amount of food eaten can affect how fast the body can process alcohol. The rate of alcohol metabolism cannot be increased by sleeping or drinking water.
Alcohol is detectable for up to 6 hours in blood; about 12-24 hours in breath, urine, and saliva; and up to 90 days in hair.
Although alcohol passes through the digestive system, it does not undergo digestion like food. When it reaches the stomach, it is absorbed directly into the bloodstream through the tissue lining of the stomach and small intestines. Once in the bloodstream, it is carried throughout the body and travels to the brain.1
A healthy person will usually feel the effects of a drink within 15 to 45 minutes.1 Most men with little to no tolerance will have some observable intoxication when their blood alcohol level (BAC) reaches 0.05%, and their ability to drive will be impaired at 0.07%. At 0.10%, they will be clearly intoxicated.2
The absorption process may be somewhat slowed when there is food in the stomach. Food can absorb alcohol, block it from coming into contact with the stomach lining, or slow its transit from the stomach into the duodenum (the upper portion of the small intestine), where it otherwise is very rapidly absorbed into the bloodstream.1
The liver breaks down alcohol with an enzyme called alcohol dehydrogenase. On average, the liver can metabolize 1 standard drink per hour for men, or about 0.015g/100mL/hour (i.e., a reduction of blood alcohol level, or BAC, by 0.015 per hour). In addition to liver processing, about 10% of alcohol is eliminated through sweat, breath, and urine.1
Factors that may influence how fast alcohol is broken down include:3
The breakdown and elimination of alcohol cannot be sped up by drinking water or sleeping, and neither coffee nor a shower will sober you up faster. As long as your rate of consumption is greater than your rate of elimination, your BAC will continue to rise.1
The amount of time alcohol can be detected in your system depends on the type of test used.
Since alcohol is metabolized fairly quickly, most clinicians rely on observations of alcohol use—such as slurred speech or the smell of alcohol—or a breathalyzer test to confirm intoxication or recent drinking.2
According to the National Survey on Drug Use and Health, roughly 14.5 million people age 12 or older had an alcohol use disorder in the U.S. in 2017. This figure represents 5.3% of all people in this age group. Alcohol-related deaths are the third-leading cause of preventable death in the country, with about 88,000 people dying each year from liver failure, overdose, drunk driving, and other accidents.5,6
Knowing more about how alcohol is metabolized and keeping track of your likely blood alcohol levels can help to prevent unintended over-intoxication and accidental death from alcohol poisoning. Understanding the dangers of alcohol can also help avoid a cycle of growing tolerance, physical dependence and, ultimately, a compulsive pattern of problematic alcohol use that culminates in addiction development.
. Bowling Green State University. Alcohol Metabolism.
. Substance Abuse and Mental Health Services Administration. (2006). Substance Abuse: Clinical Issues in Intensive Outpatient Treatment.
. United Kingdom National Health Service. (2018). How long does alcohol stay in your blood?
. American Society of Addiction Medicine. (2013). Drug Testing: A White Paper of the American Society of Addiction Medicine.
. Substance Abuse and Mental Health Services Administration. (2018). Key Substance Use and Mental Health Indicators in the United States: Results from the 2017 National Survey on Drug Use and Health.
. National Institute on Alcohol Abuse and Alcoholism. (2018). Alcohol Facts and Statistics.