“Raw” peptides like tirzepatide are a near pure API and are Lyophilized Compounding pharmacies buy bulk raw API peptides from China. For example southend in Texas uses this company see COA pic from their website …FDA registered …. huge company, partly owned by a German company… The rep only sells to licensed pharmacies in the United States.
I have tested 2 different raw tirzepatide by amino acid sequencing, and HPLC. Both tested well. I attached the AA sequencing done by a college based research facility specializing in peptides.. you can actually look at the result and see what AA make up the non- tirzepatide sample.
So most compounding pharmacies just mix the raw peptide with a solution, such as B12, bacteriostatic water or saline….
Compounding pharmacies buy from a FDA registered manufacturer directly, they test for sterility and potency. The smaller pharmacies use syringe filters and it is endotoxin tested. Bulk pharmacies uses huge filter that’s positively charged that also removes endotoxins. The endotoxin test is very expensive because it is made from the blood of horseshoe crabs.
It is smarter and cheaper to buy a finished product from a reputable compounding pharmacy in business for many years . The raw peptide could have been anywhere after leaving the plant