the overfill threads are some of my favourites to read because people are paying close attention to what they actually got in the vial, and that instinct is correct. measuring your draw, noticing the 60mg label gave you 69-70mg, asking why one pharmacy runs hot and another runs lean. all good habits. so this isn’t a correction of the noticing. it’s a gentle push on what the overfill tells you. here’s the thing it doesn’t tell you: potency. overfill is a fill-volume decision at the bench, not a statement about how much active drug is in solution per mL. a vial labelled 60mg can carry extra volume for a few reasons. some of it is genuine generosity in the fill, some of it is built-in compensation for the loss you take to the stopper, the needle, the dead space, the residue that clings to the glass. a facility that knows operators will lose a couple of mg to mechanical waste may fill past label on purpose so the patient still gets their full labelled course. that is a kindness, not a bonus. the 9-10mg you found on top of 60 may be exactly what the next person’s vial loses to the rubber. and the part that gets collapsed: total mg in the vial is not the same as mg of intact, correctly folded tirzepatide per mL three weeks into your beyond-use date. a peptide can be present and still be degrading. you can have generous overfill and falling potency at the same time, because those are two different questions answered by two different measurements. which is where i’d point anyone who actually wants to know what they’re injecting. a certificate of analysis is a release-point snapshot. it tells you potency and sterility at the moment that lot was tested at the facility, before it shipped, before it sat in a fridge, before you reconstituted it. it is a real and useful document. it is not a guarantee of what your specific vial is doing weeks into its BUD after a temperature excursion in transit. overfill volume tells you even less about that than the COA does, because volume isn’t potency at all. so by all means keep measuring your draws. the granularity is good and it keeps pharmacies honest on fill. just don’t read a fat vial as a quality signal. the quality signals worth chasing are third-party lot testing, honest BUD assignment for the formulation and storage you’re actually using, and a pharmacy that will talk to you straight about both. if you’re tracking anything across a titration, log the lot number alongside your dose and any change in how it feels going in. cloudiness, sting, a batch that seems weaker. that running record is far more telling over time than the mg you found on day one of a single vial.