How to check if a store is fine

Hello all,

I apologize if this is not the correct place to post this. I was searching for the VT cosmetics collagen reedle shot and it's sold out everywhere but not at a shop called Cosmadic.de

I've never heard of it, but google reviews are very good. I've looked through their shop and they are quite a bit cheapter than other stores.

How can I check to see if I would be buying fakes? Has anyone ever bought anything from them?

How do you in general make sure to only buy the original deal?

Thank you so much