vitamin b12 injection weight gain Beyond the Needle: Unpacking Injections and Your Body GLP-1 + NAD+ + B12:

A rare case involved a woman who had immediate adverse reactions to both cyanocobalamin and hydroxocobalamin, by both injection and oral delivery

Weinheim: Wiley-VCH

The difference between pulling 1 unit and 2 units is a 100% dosing error, and at that scale, the margin for mistake is unacceptably thin

Johns Wort can accelerate clearance and diminish efficacy, whereas inhibitors like ketoconazole, clarithromycin, certain protease inhibitors, or excessive grapefruit intake may elevate serum estradiol and increase adverse-event risk

However, it may also result from a range of underlying health conditions, like chronic pancreatitis, SIBO, and malabsorption disorder