A dose change is the one moment where a thin log costs you. Everything before the change becomes a baseline you may want to compare against, and if the baseline is vague the comparison is worthless.
Here is what actually needs to be on the page when the number moves.
The old dose and the new dose, in mg. Not in units. Units are a property of your current vial concentration, and the moment you mix a new vial at a different strength, a unit count from last month means nothing. Milligrams travel across vials, units do not.
The units for the new dose, and which syringe. This is the operational number you will use for the next few weeks, and it is worth writing down once rather than recomputing every time. If you are not sure how to get from mg to units on your particular vial, the reconstitution calculator does that conversion directly.
The date, and the reason. Scheduled step up, plateau, side effects settling, supply gap. In three months the reason is the part you will have forgotten and the part that matters most.
Where you were before. Weight if you track it, appetite, whatever your one or two headline measures are. A snapshot on the day of the change, so you have something to compare to rather than an impression.
Anything else that changed that week. New vial, new batch, travel, illness, a different injection site. If something unexpected happens after a dose change, the first question is always whether the dose was the only variable. Usually it was not.
I keep the whole thing as one row with a note field rather than a separate journal entry, because a separate journal entry is a thing you write once and never open again. If a term in your own notes stops making sense later, the glossary is a reasonable place to check yourself.