[BigGirk]

In Canada, it's policy, perhaps a requirement, for doctors to tell you most self-medicating methods won't work even if they know they work. They do this to prevent people from making their health issues worse as a result of self-treatment.

Of course, this may also just be the candy coated "official" reason, with the fact they also get paid more for using OHIP certified treatments likely having more to do with it than anything else.