Has anyone dealt with ⚠ peptidemeter exposed: some vendors scoring e grade on basic peptides?

One thing that is still open after carl_compliance’s answer:

How long did you give it before you decided it was working?

BethLabQueen said:

My vendor review relevant to certificates of analysis: ordered 4 times from my current compounder.

I tested my certificates of analysis batch through Janoshik — 97.3% purity. That's within acceptable range for compounded peptides. Turnaround was 8 business days.

The test costs ~$147 but gives you actual HPLC chromatography data plus mass spec confirmation. For the peace of mind alone, it's worth every penny. I test every new batch from a new vendor.

BethLabQueen said:

My vendor review relevant to certificates of analysis: ordered 4 times from my current compounder.

Agreed, with a caveat about community reputation: it is a lagging indicator. Reports arrive weeks after orders, so a supplier can look excellent for a month after quality has already changed.

Worth separating that from vendor vetting, which this thread keeps folding into the same question. They behave differently and the advice does not transfer.

That is the short version; the long version is somebody else's post.

BethLabQueen said:

My vendor review relevant to certificates of analysis: ordered 4 times from my current compounder.

Bookmarking. The distinction being drawn above is the one nobody else makes.

Reporting back.

Went back through my own correspondence with an earlier supplier and the warning signs were all there in the replies, weeks before the quality changed. I was reading the product and not the behaviour.