A supplier that answers analytical questions with restated claims

On post #11 — agreed on the reasoning, with one qualification.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

post #15 answers the question as asked. The question underneath it is different.

Safety documentation absent: a supplier that cannot provide information about sterility testing, endotoxin testing, or safety documentation when asked is raising flags.

Inability to trace lots: if you ask "where was this synthesised, by whom, under what conditions" and cannot get a clear answer, that is a red flag. Traceability is not glamorous but it is foundational.

Worth separating two things that post #15 runs together.

Documentation quality as a signal: a supplier that reports method identifiers, distinguishes specification from result, and states the counter-ion form is telling you something about systems behind the document. A certificate that is a number and a signature tells you less.

Evasion when asked: if a supplier does not clarify when asked specifically for method details, counter-ion form, or batch origin, that itself is a red flag worth documenting.

Pricing patterns: unusually low prices for what are otherwise consistent with market rates might indicate lower quality, stolen goods, or a scam. Unusually high prices without justification raise different flags.

Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.

The correction was fair and I had been repeating something I had not checked carefully enough.

Picking up post #20: that is the part I would want checked first.

Exaggerated claims without documentation: every compound has limits. No peptide is "100% pure" because purity is measured to finite precision. A supplier claiming implausible perfection without backing evidence is overreaching.

Unresponsiveness: a supplier that does not reply to reasonable requests for documentation or clarification is showing you something about how they operate.

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

Patterns that reliably precede a problem: underdosing (less active material than stated, documented by independent testing), mislabelling (wrong compound, wrong strength, or wrong batch on the label), and failure to provide documentation when asked.

This follows post #24 rather than contradicting it.

Anonymity: a supplier that will not disclose legal name, address, or responsible person is not operating in a way that allows accountability.

I read post #26 twice before replying, because I had assumed the opposite.

Safety documentation absent: a supplier that cannot provide information about sterility testing, endotoxin testing, or safety documentation when asked is raising flags.

post #28 answers the question as asked. The question underneath it is different.

Unresponsiveness: a supplier that does not reply to reasonable requests for documentation or clarification is showing you something about how they operate.

On post #26 — agreed on the reasoning, with one qualification.

Inability to trace lots: if you ask "where was this synthesised, by whom, under what conditions" and cannot get a clear answer, that is a red flag. Traceability is not glamorous but it is foundational.