High-Performance Liquid Chromatography so purity and concentration.

Back when I started few people were doing this and it was more of a risk, I was buying from research peptide vendors who had their own testing practices, but now a huge number of people are doing it and there are markets where reputations matter and it appears to be a reasonably efficient.

I would prefer not to inject peptides from gray market China but practically all of the gray/black market supply is from there. I will likely switch to pharma grade when generics become available.

Im a libertarian at heart so cant argue too much with people's personal choices, but I can only say that given what I know can go wrong in even the best maintained lab, I wouldn't ever do what youre doing. Yes its all great today, but the day something goes wrong, you may not be happy finding out how its affecting you. Look up the bayer factor viii hiv incident.

Things go wrong all the time, it's a balance of risks / rewards given the information we have. For me the cost of doing nothing is that I succumb to ME/CFS and end up homeless in addition to still having ME/CFS which might as well be a death sentence.