Heres your answer. No peptides from these peptide and research companies are not distributed by pharmacies or created by pharmacies. So no, you dont have any guarantee as to what is in the vial or if it contains what they say it contains.
You can try them if you want but they are not going to make you big. Not any bigger than a good diet and training regimen.
They have minor benefits in some cases but are not nearly as effective as aas. Ive used many of these peptides at one time or another, on the off chance i see something come out of them, and i will continue to try different things here and there. But ypu are not going to achieve any major gains from these peptides, regardless of what the label or website claims.