Active ingredient in Marinol is Delta 9 THC and its major metabolite is THC-COOH, same thing that they will test for when you fail immunoassay and it goes to GC/MS. So both marijuana and Marinol have the same active ingredient and the same major metabolite they will look for on GC/MS. Make sense?

Thing is, depending on the state, probation doesn't have to accept your Marinol script. You better let them know before you start taking it.