Know the Facts

Helping you make informed decisions about your drinking

Metabolism of Alcohol

Our bodies do not store alcohol, so alcohol has to be processed and removed as we drink it. Most of this job is done by the liver. The 10% of alcohol not processed by the liver is removed through our urine, sweat and breath.

  1. Alcohol is ingested through the mouth.

  2. Some alcohol is absorbed by the stomach and enters the bloodstream

  3. Remaining alcohol passes into the small intestine where it is rapidly absorbed.
    About two-thirds of the alcohol you drink is absorbed here.

  4. Alcohol travels through the blood to all parts of the body

  5. In the liver, alcohol is broken down by an enzyme called alcohol dehydrogenase (ADH).
    The alcohol is converted to acetaldehyde, then to actete, and finally into carbon dioxide and water.

Factors that influence the metabolic process

Food in your stomach

Having food in your stomach will slow down the rate of alcohol absorption. This means it won’t enter your bloodstream as quickly, and your blood alcohol concentration won’t rise as quickly.


Women have a lighter body weight and a slower activity level of the enzyme ADH. Because of this, women don’t break down alcohol as quickly as men, keeping more of it in the blood.

Liver health

Damaged and unhealthy livers have a reduced ability to break down alcohol, keeping blood alcohol concentrations higher for longer.


The liver enzymes used to break down alcohol differ from person to person, depending on genetic make-up. These enzymes work at different rates, meaning some people will naturally process alcohol faster than others.


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  • Forrest, E. & Reed, E. (2011). Alcohol and the liver. Medicine, 39, 532-535.
  • Paton, A. (2005). Alcohol in the body. British Medical Journal, 330, 85. doi: 10.1136/bmj.330.7482.85
  • Suter, P. M. (2005). Is alcohol consumption a risk factor for weight gain and obesity? Critical Reviews in Clinical Laboratory Services, 42, 197-227. doi: 10.1080/10408360590913542
  • Suter, P. M., Hasler, E., & Vetter, W. (1997). Effects of alcohol on energy metabolism and body weight regulation: Is alcohol a risk factor for obesity? Topics in Clinical Nutrition, 55, 157-171.