Tolerance is:
the power or capacity of an organism to tolerate unfavorable environmental conditions;
a disposition to allow freedom of choice and behavior;
the willingness to recognize and respect the beliefs or practices of others;
a clearance between surfaces allowing some freedom to move within limits;
the range on what is allowable on a dimensional specification.
Tolerance is the capability to bear stressful condition. It can be enviornmental like heat, cold etc. or it can be mental like emotions of sadness or happiness. The extent of tolerance or the extent upto which a person can bear the stress is called its tolerance power.
With tolerance, it takes more alcohol to achieve the same effects that lesser quantities created before tolerance developed.
I am on methadone and have been for years. I am also taking college courses, one being Psych Substance Abuse and Addiction. The answer is until the methadone is out of your system. It may take days, weeks, or months. For me, it would take months, but if you took methadone but you're not used to taking it, probably a few days or so. Methadone does block the effects of heroin, which is why a lot of people use the methadone maintenance treatment programs. If I were to try to use heroin tomorrow, it would just be a waste of time and money because I wouldn't even feel it, and I would hella pissed, which is the purpose of it blocking the heroin. The withdrawal from methadone can take weeks or months, and it's more intense than heroin.