text: how long dose it take for alcohol to leave the human system?   just read this in my biology book yesterday.  breaking down alcohol. the liver, the only organ able to break down alcohol in the body, removes the alcohol from the bloodstream by slowly converting in into another poison, acetaldehyde; this poison is responsible for the headaches and nausea ("hangover") that follow alcohol consumption. the acetaldehyde is eventually changed to acetate and  "burned" in cellular respiration. because alcohol remains in the body until it is broken down by the liver, it may take the body hours to rid itself of only a few drinks. also keep in mind that it mainly depends on your wait. if a person weights 100 pounds and they consume 1 drink = .038% is there blood level, 2 drinks = .075% driving becomes drangerous and you are legally drunk in some states at .08%. or a person, 160 pounds can drink 2 drinks and have there blood level at .047%, alittle over what a 100 pound person's blood level is at after just 1 drink. so as i said it largely depends on your weight. hope this helps!