Getting supplements and specific drugs from pharmacies: how?

Mandarin ability severely limited here. There’s plenty of doctors around, but, how many of them sell specific drugs?

I’m looking for a specific non-prescription drug that you can get in the states, Priacetam (Nootropil), a supplement, but I’m not sure where to start. I know that most doctors have memorized the names of medications, but I’d like to save my time and ask the friendly people here what part of town would have a pharmacy friendly to making requests.