Birn H, Zhai X, Holm J, Hansen SI, Jacobsen C, Christensen EI, Moestrup SK
they are not for human consumption, medical, diagnostic, cosmetic, veterinary, or any other non-research application
A peptides certificate of analysis should be independently verifiable meaning it comes from a third-party lab rather than the suppliers in-house testing alone since that independence is what gives the purity claim scientific credibility
Swirl gently (no shaking)
(Second on my list would be vitamin D, but its much harder to develop low vitamin D levels if you take a daily supplement, as I explain in this post
Similarly, B12 is classified not for its chemical nature (a vitamin) but for the high-risk administration route (injection) and the severity of the condition (Pernicious Anaemia) it treats