Since you didn't say what a "dm shop" is, I'll assume you mean "dungeon master shop" where you buy Dungeons and Dragons-y stuff.

Or maybe it's a "direct marketing shop", where you bring flyers to be delivered into people's mail? Yeah, that must be it.

Given that it's about food or medicine somehow, because of the mention of ingredients lists and health-related information, it's probably https://en.wikipedia.org/wiki/Dm-drogerie_markt (usually abbreviated "dm").

(I didn't know about that either before now.)