Not well regulated im afraid. A pharmacist can dispense it if you provide identification, but its open to and does get abused, which is why it's being closed. I'm not sure where that fits into the heroin trade, as the heroin epidemic was before my time in the job.
My gut feeling is Dr shopping tends to be people with chronic pain who have then become addicted, where the earlier heroin epidemic was more based in recreational drug use, but i have nothing to back that statement with.