I only recommend one source. The lab below runs regular third-party testing and meets the standards I hold my own protocols to.
TPG10
I do not recommend sources casually. Origin Research runs regular third-party testing for identity confirmation, purity, endotoxins, and heavy metals. That level of verification is not a bonus, it is the baseline for responsible use.
Sourcing is not a detail. It shapes everything that follows.
This is the only source I personally use and recommend. Your biology deserves the same standard I hold my own protocols to.
Sourcing is one piece. Knowing which peptides to source, at what dose, and in what order is another. That is what the consultation is for.