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c/coa·posted 2 months ago by u/coa_janitor

am I the only one who found COA harder than the injections

Suspicious Well Actually ×2 Sourced ×1

Been lurking in c/tirzepatide for about 15 months and finally have something worth posting.

Short version: week 5, 7.5mg, and water content is the bit I still cannot get a straight answer on. I have read the wiki, I have read the last 27 threads, and the answers split roughly down the middle.

What I actually want to know is whether the people saying it does not matter have measured it, or whether it is just repeated confidently. Happy to be told I am overthinking this — I probably am — but I would rather overthink it now than at week 94.

1,425 up / 362 down80% upvoted40 commentsid zfzzi32 May 2026

40 comments

12 in this archive, depth 3

best — the order this archive was captured in

u/gallbladder_gary-10 points·2 months ago

This is the correct framing. The COA structure matters as much as the number.

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[removed]1 point·2 months ago

[removed by moderator]

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u/anecdata_annie1 point·2 months ago

Tested the GLB raw material and a reseller vial side-by-side. Same purity claim, different impurity profiles. Handling matters.

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u/milos_vanhecke1 point·2 months ago

Yeah, 96.8% area is not the problem, the missing impurity breakdown is the problem.

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u/gastric_emptying_g106 points·2 months ago

What were the related substances listed individually?

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u/tove_ogunleye87 points·2 months ago·edited

purity and net content are two different numbers, same vial

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u/coa_janitorOPmod · c/coa37 points·2 months ago

Did they give you the chromatogram or just the summary line?

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u/ahmed_rasmussen60 points·2 months ago

redact your own name, not the vendor's batch details

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u/coa_janitorMOD79 points·2 months ago

Retitled to remove editorialising. Put the evidence in the body.

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u/ahmed_rasmussen55 points·2 months ago

Yeah, 96.8% area is not the problem, the missing impurity breakdown is the problem.

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u/meera_sandvik38 points·2 months ago

the method line is doing real work, not just window dressing

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u/coa_janitorOPmod · c/coa28 points·2 months ago

axis labels included, always

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About c/coa

How to read a certificate of analysis and what it does and does not tell you. Area% versus mass%, identity versus quantity, water content, related substances, acetate counterions, and the difference between a vendor-supplied COA and an independent test on the vial you actually received.

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