Cobalamin blood levels can be monitored, and many veterinarians prefer to check these levels at the time of diagnosis for GI disease, as well as periodically during treatment, to determine if B12 levels are remaining normal
[1] As a compounded product, it is not an FDA-approved commercially manufactured drug
The deltoid and gluteal muscles are common sites for these injections
But beware, there is a tendency for the doctor to think the more symptoms a person reports, the more likely the cause of the symptoms is psychological
References Cox HD, Smeal SJ, Hughes CM, Cox JE, Eichner D
Retatrutide is an investigational GLP-1, GIP, and glucagon triple receptor agonist currently in Phase 3 trials