“How to help a young adult who is addicted to meth?”

Unfortunately, Findatopdoc.com does not provide me with dates of when questions were asked, so I don't know how long it has been since you asked your question and I'm sorry if this response is late.

You can't do anything other than love and support him without supporting the drug use. You can set boundaries and tell him your expectations and how you want your life to look with him in it. You can give him options and recommend he go to a substance abuse treatment center, but ultimately, he has to make that choice and reach out for help. Beyond that, he needs to be in mental health therapy to work through whatever issues he has that are underlying his drug use. While 12-step programs can be helpful, they are unlikely to "fix" the problem, as some research shows they only have a 3-5% success rate.

There is no solid medical treatment for methamphetamine addiction. It's something that mostly is addressed from a behavioral standpoint. Does he want to get better? If not, then you should try to help him figure out what he wants.

Most meth addicts require a few weeks in an inpatient rehab to successfully stop using, since for the first two weeks the craving to resume meth is simply overwhelming. Vox.com has a terrific article on how to find a competent rehab program, since so many are incompetent. Good luck!