b12 injection with tirzepatide B12: the complete guide to compounded formulations Tirzepatide Injection HomeKit

I can't see any blood test results for iron eg ferritin or any other iron tests

This is a valid option, especially for microdosing protocols where you need very precise measurements of small doses

Coskun Mol Metab 2018

Yes , for any in vitro biological assay where the reconstituted peptide is added to cell cultures or tissue preparations, matched Bacteriostatic Water vehicle controls at the same final benzyl alcohol concentration as the highest peptide treatment concentration should be included to confirm absence of benzyl alcohol-mediated biological effects on the assay endpoints measured

B12 (Cyanocobalamin) Vitamin B12, essential for DNA synthesis, fatty acid metabolism, and amino acid metabolism