Hi E!
Im relatively new to the game too, but what I've gathered so far has been pretty great! I watched this video that Randy made about how to read the COA's from companies. Super helpful!
https://www.youtube.com/watch?v=FNzvaiD43go
I have been purchasing from a compound lab called
Mile High Compounds - its been great so far! However, check out EZpeptides (I've heard and seen good things about that company) and the vendor directory in this site. I really like looking over the reviews to get a good grasp on what people are seeing.
What I'm doing is going to the well-reviewed pages, looking up the exact peptide, and comparing the COA's to each other from what I understand them to be. Definitely dive into your own research and look around! It's a crazy world out here these days! lol