How do pharmacies handle controlled-substance ADHD prescriptions across provinces?

Pharmacies handle controlled-substance ADHD prescriptions across provinces under provincial pharmacy standards plus federal CDSA rules, not under a single national fill-anywhere policy. An out-of-province stimulant prescription may not be fillable. The receiving pharmacist decides based on authenticity, the licence of the prescriber, and provincial rules. References: https://www.napra.ca/ https://www2.gov.bc.ca/gov/content/health/health-drug-coverage/msp

I tried to fill a controlled ADHD script from one province in another and the pharmacist said they had to check things I did not understand. I stood at the counter feeling like I had done something shady. I had not. I went home and called a local clinic instead of arguing. This is just my counter experience, not a rulebook for anyone else.