b12 injections im or subq Methylcobalamin Injection (Vitamin B12) B12 Shots vs. IV Infusions:

I have taken the Lipo/B12 shots for going on three months

Dosage may be reduced to 0.5 mL weekly in patients experiencing gastrointestinal intolerance or increased to a maximum of 2 mL twice weekly for short-term metabolic intensification when supervised by a qualified clinician

10.1186/s12986-022-00653-9 171 ZhouQ.HuangZ.-G.ZhuX.-J.XieZ.-H.YaoT.-F.WangY.-H.et al (2018)

In terms of receptor complexity, yes , Retatrutide engages three receptor systems while Semaglutide targets only GLP-1 receptors

As such, having inadequate B12 levels can decrease normal red blood cell production, which can impair oxygen delivery ( Specifically, a deficiency in B12 can cause megaloblastic anemia