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[2026 update] A certificate with no method stated: what can you conclude?

Analytics › COA interpretation reference standards certificate of analysis documentation quality batch & lot numbers

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Solved by VThorvaldsen in post #3

Endotoxin testing is separate: a certificate of purity says nothing about endotoxin. A chemically pure preparation can carry a clinically significant endotoxin load. If endotoxin matters, it needs to be tested and reported.

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IbrahimoviTL2Member4 Sep 2025#1

A certificate with no method stated: what can you conclude? — that is the question, and I have not found it answered plainly anywhere I have looked.

I would like to understand what this number means before I repeat it anywhere.

A Medutest report on a retatrutide lot gives 97.2% purity. The supplier certificate for the same lot states 97.6%. Both documents name a reversed-phase method; neither states the same gradient.

My question is not "who is right". It is: given that those two figures were produced by different methods, what is the largest difference I should expect from method alone, and at what point does a gap stop being explainable that way?

12 likes 11mo

i.rasmussenTL27 Sep 2025#2

The opening post and I disagree about the size of the effect, not about the direction.

A certificate of analysis is a statement by its issuer that a defined test was performed on a defined lot and produced a defined result. That is all it is, and it is not nothing. What makes it usable: lot identifier matching the container, test date, method identification specific enough to reproduce, the actual result as a number, and the acceptance criterion stated separately from the result.

16 likes 11mo

VThorvaldsenTL3Regular Solution10 Sep 2025#3

Ibrahimovi, post #1: A certificate with no method stated: what can you conclude? — that is the question, and I have not found it answered plainly anywhere I have looked. I would like to understand what this number means before I repeat it anywhere. A Medutest report on a retatrutide lot gives 97.2% purity. The supplier certificate for the same lot states… Go to post

Endotoxin testing is separate: a certificate of purity says nothing about endotoxin. A chemically pure preparation can carry a clinically significant endotoxin load. If endotoxin matters, it needs to be tested and reported.

7 likes in reply to #1 11mo

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Specification in the result column: why that is a meaningful error — the long versionAnalytics › COA interpretation · 18 replies

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