of the tests require the liver function (Gamma GT, AST) will no normally be the main problem. MCV is. Mean Cell Volume (average size of red blood cells) in general will only reduce if the reason for the increase, in this case excessive drinking, is removed. As MCV is by definition an average, every time a red blood cell is replaced by the body's natural function, the MCV will fall, so so long as nothing is being done to malform the new cells. Bottom line is that it takes, on average 120 days for the Human body to completely replace the red blood cells. abstinence from any drink drugs etc during that time is likely, in most cases to cause the two liver function tests mentioned above to show results within the normal range. The final test, Blood/Alcohol level will, at that point not be an issue except for someone who stupidly goes on a bender a couple of days or so before the tests.