Hi there,
I don’t take metformin. But here is some NHS advice on the medication & a brief section on recommended timing of it?
NHS information about the medicine metformin, including what it's used for, who can use it, how to use it and side effects.
What insulin are your prescribed?
Regarding the metformin interacting with your insulin dose. Speaking with your pharmacist & or doctor for some rough guidance.
It will be a little trial and error fitting the meds with your lifestyle.
Keep testing bloods & logging results to spot a general trend.
Best wishes.
Jay.