u/aurel_boateng

Water content was 3.8%, acetate was 6.2%, purity was 99%, but net peptide was only 90% of the label weight. Perfectly honest, just chemistry.

Small correction: the trial was 2 weeks, not 25. Does not change your point but people will quote it.

The first time question took me three weeks to understand. Wiki explained it eventually.

The injection was scarier than the first time itself. 23 seconds and I was shocked it was the easiest part.

Week 10 checking in: nothing on the scale, no nausea, wondering if the pen is broken. No, it is just week 10.

the normal question is not dumb

The single most useful thing I did was write the concentration on the vial. Stopped all the confusion after that.

Not to be pedantic but water content and area percent are being used interchangeably and they are not interchangeable in real life.

the related substances line is where the story is

The evidence standard in c/vendorvetting gets called too strict about once a month, and every time, the thread ends with the complainant agreeing.

Water content matters more than people think. If a vial is carrying residual moisture, your "10mg" is not 10mg of peptide.

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

Inter-lab variance on this kind of assay is routinely 1–2 points. Different column, different gradient, different integration.

stopper coring on the 2th draw because you keep using the same entry point. rotate.

the related substances line is where the story is

Sent one vial to PeptideMeter and VendorInvestigate.

Adding to this: batch is doing more work than the comment implies.

Show the arithmetic. Where did the units come from?

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