The idea that throwing up will immediately sober a person up is a common misconception about alcohol consumption. Intoxication, measured by Blood Alcohol Concentration (BAC), reflects the amount of alcohol currently circulating in the bloodstream, not the amount remaining in the stomach. Vomiting may remove unabsorbed alcohol from the digestive tract, but by the time a person is intoxicated enough to feel nauseous, the alcohol has already passed into the circulatory system. Therefore, vomiting does not reliably reduce a person’s current level of impairment.
The Speed of Alcohol Absorption
Alcohol is a small molecule that begins to enter the bloodstream almost immediately upon consumption. While a small percentage, approximately 20%, is absorbed directly through the lining of the stomach, the bulk of alcohol absorption occurs rapidly in the small intestine.
When the stomach empties its contents into the small intestine, the remaining alcohol is quickly absorbed into the blood. For an individual drinking on an empty stomach, the peak BAC can be reached within 30 to 120 minutes. This means that long before the body triggers a vomiting response due to high alcohol levels, the substance has already left the digestive system and is actively affecting the brain and central nervous system. Throwing up at this stage only removes stomach contents, which are mostly food, water, and perhaps a small, residual amount of alcohol.
How the Body Actually Processes Alcohol
The only mechanism the body has for reducing the Blood Alcohol Concentration is through metabolism, which primarily occurs in the liver. More than 90% of the alcohol consumed is processed by this organ. The process begins with the enzyme alcohol dehydrogenase (ADH), which converts alcohol (ethanol) into a highly toxic compound called acetaldehyde.
Another enzyme, aldehyde dehydrogenase (ALDH), then quickly breaks down the acetaldehyde into acetate. The liver can only process alcohol at a relatively fixed rate, which is approximately a decrease of 0.015% in BAC per hour, equating roughly to one standard drink per hour. No external actions like drinking coffee, taking a cold shower, or inducing vomiting can accelerate the speed at which the liver’s enzymes perform this chemical breakdown.
Vomiting as a Sign of Alcohol Poisoning
Vomiting should not be viewed as a means to sober up, but rather as a defense mechanism the body employs to expel toxic levels of alcohol. When a person drinks too much, the central nervous system becomes severely depressed, which can lead to a loss of the protective gag reflex. This loss creates a situation where a person who is unconscious or semiconscious can choke on their own vomit, a potentially fatal event known as aspiration.
Severe vomiting is a clear indication of alcohol poisoning, which is a medical emergency. Other signs include confusion, seizures, or a low body temperature. Breathing that is slow (fewer than eight breaths per minute) or irregular (a gap of more than 10 seconds between breaths) signals a dangerous level of intoxication.
If a person has consumed a dangerous amount of alcohol and cannot be woken up, or exhibits any of these severe signs, call emergency medical help immediately. While waiting for help, the person should never be left alone and must be turned onto their side to prevent choking if they vomit. Attempting to force a person to vomit is strongly discouraged, as it can increase the risk of aspiration and injury to the esophagus.