Its not a scheduled controlled substance like juice, its a prescription only drug. So letsay you get pulled over its is unlikely anything would happen, but it depends on the cop, if he is a rookie, and if he is in a good mood that day. Technically you shouldnt have it without the script but chances are low of getting busted for having it because its not like they would get a good charge on you like for illicit drugs.
For example you could roll across the mexican border with it and declare it and they would have to let you in with it unless you are bringing some huge supply. Dont try that with juice.