Comment by cthalupa

Janoshik is the primary company people use here, and their business is basically entirely peptides and anabolic steroids, and the GLP-1 stuff exploded their business from gym bros to soccer moms everywhere. https://janoshik.com/

But they basically test the same 12ish compounds day in and day out, with another couple of dozen making up the remainder. They don't have most of the worries that you are referring to - first time for a tech running a specific set of standards, limited experience interpreting them, etc., and when people head to head their results against different labs, they are consistent.