Something I don’t see discussed much when people share their tirz titration journeys is what happens when a compounding pharmacy changes their batch concentration mid-protocol. Not the dose printed on the label. The actual concentration in the vial. I ran into this with CJC-1295 about eighteen months ago. The label didn’t change. The instructions didn’t change. But at week two of a new batch, the dose felt noticeably off – not dramatically, just wrong in a way I couldn’t place. Enough that I called the compounder and confirmed they’d quietly shifted from 2mg/mL to 5mg/mL between batches without sending any notification. Same label, different powder. The reason this matters for compounded tirzepatide specifically is that these vials come in genuinely variable concentrations depending on the pharmacy – 2.5mg/mL, 5mg/mL, 10mg/mL are all in circulation. If your pharmacy swaps the batch, your volume math is suddenly wrong even though the label says you’re on the same dose. Someone who’s been tolerating 15mg and receives a new vial at a lower concentration is effectively stepping themselves back without realising it. The reverse is also possible, and more concerning. What I’d suggest: whenever you start a new vial from a compounded source, do a quick sanity check before injecting. Calculate the volume you should be drawing based on the stated concentration, and compare it to what you were drawing from the previous vial. If the numbers don’t line up, call and confirm the batch specs. Takes two minutes and it’s caught me out once already. Titration is hard enough without the variable being the vial itself.