How long does alchohal stay in your blood?

Alcohol is generally no longer detectable in one to two hours, depending on the size and sex of the person. This also assumes one, one-ounce drink of alcohol, with no alcohol ingested for several hours or days before that. One ounce of alcohol will have a greater effect on a 100-pound female than it will on a 300-pound male. And whether fair or not, alcohol stays in a female's system longer than a male's because of the fact that women metabolize alcohol differently than men do.