u/emeka_beaulieu

chromatogram or it did not happen

Yes, exactly this, and it is the bit that took me 66 weeks to accept.

the counterion is part of the mass you paid for

The COA I was holding said 96.8% area and I thought it was trash. Turns out the method was solid and the impurity profile was clean.

Sent one vial to PeptideMeter and VendorInvestigate. 98.4% and 98.0%. Cost me more than the vial did and I would do it again.

The chromatogram trace is where the real information lives. The summary number is just a headline.

Yeah, data logger is the only acceptable proof.

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

Edit to your parent would help — the concentration you quoted assumes one scenario and you have written another above it.

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

Reconstituted or dry powder?

That is net peptide content, not purity. Different number, different meaning.

batch number?

Counter-anecdote: opposite result, same dose. Which mostly tells us the variance is huge.

Strongly agree. Mass% and area% are answering different questions on the same document.

area% is not mass%, and here is exactly why it matters

private 1.0mg is MHRA in Ireland this month

Yeah, data logger is the only acceptable proof.

Strongly agree.

Yes, exactly this, and it is the bit that took me 43 weeks to accept.

France to France takes 12 days on average, variance is 16 days

lyophilised powder is far more forgiving than reconstituted solution

Disagree on that part. 99.2% and 99.3% on the same vial is normal.