Get your peptides from licensed compounding pharmacies or online vendors that provide a Certificate of Analysis proving purity. Aim for 98-99% purity, ideally 99% or higher. Verifying your source matters more than where you buy.
My second rule is know the source. Now, compounds that are coming from online sources are categorically different than those that are coming from licensed compounding pharmacies or sources where there is purity testing. That is critical. You will find a lot of sources for peptides, but knowing the quality is very important. What I advise to people is that they obtain these from compounding pharmacies and they look for certificate analysis. And if they're getting it from an online source, they ensure there's purity testing. Any responsible provider of peptides will provide certificate of analysis testing, which can ensure you as a consumer that what is in there is actually what is reported to be in there. And I would look for 98 to 99% purity. 99% and better is certainly ideal.
