Coming back to: Pricing far outside the range, in either direction

Pricing far outside the range, in either direction Writing it up because I had to work it out twice and would rather nobody else did.

Structured report rather than an opinion, following the format the maintainers asked for.

• Compound: tirzepatide
• Independent testing: Janoshik
• Method as reported: reversed-phase HPLC, 220 nm
• Result: 99.1% area
• Certificate figure for the same lot: 98.7%

I am not drawing a conclusion about the supplier from one lot and I would ask that nobody else does either. I am adding a data point to a record.

the opening post is right about the mechanism and I think understates the practical bit.

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

Inconsistency across documents: a certificate stating one purity, a website claiming another, and a supplier's verbal representation claiming a third, all on the same product, is a red flag for either incompetence or deception.

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.

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.

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

Coming back to post #5, because the follow-up matters more than the original answer.

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

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.

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.

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.

Rapid supplier turnover: a supplier that changes corporate structure, domain name, or contact repeatedly in short time windows raises suspicion about stability and legitimacy.

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.

Picking up post #10: 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.

Coming back to post #12, because the follow-up matters more than the original answer.

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