u/rosa_mensah

30mg vial, 2mL water, concentration is 30/2 — write it on the vial afterwards

Every time this gets posted it hits the front page and every time someone has to re-explain it.

stopper coring on the 3th draw because you keep using the same entry point.

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

dead space is real and the syringe matters

show your working or it is unhelpful

bacteriostatic and sterile water are not interchangeable, do not use them that way

the concentration on the vial in marker is the most important step

Cored the stopper on my 5th draw because I kept using the same entry point. Rotate the puncture site.

The practical rule people converge on is 28 days at fridge temperature after first puncture, and that comes from the preservative, not the peptide.

Cosigning.

Adding to this: mg/mL is doing more work than the comment implies.

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

Yeah, showing the arithmetic is the fastest way for someone to spot the error.

swirl, do not shake, or you are courting oxidation

Are you using a u-100 or u-40 syringe? That changes everything.

u-100 syringe, not u-40, or your math is off by factor of 15

Yeah, showing the arithmetic is the fastest way for someone to spot the error.

Spent 20 weeks confused about concentration math until someone showed me the table. 5mg, 2mL, concentration is 5/2.

Not convinced. The evidence does not support that reading.

Slight fix: the number was 96.8, not 99.1. Decimal point, but a fairly consequential one.

The confident tone is doing a lot of work that the evidence is not.