If your lab is asking 'which one should we use,' the real question is: what biological pathway are you studying
6 weeks 42 syringes 1 syringe per injection
But if you're dragging despite sleep, dealing with unexplained weight resistance, or you've tested low for B12, it's worth the conversation
No comprehensive, long-term human safety studies have been published
How B12 Injections Work: The injection process is straightforward and quick
More specifically, the superior mesenteric vein, inferior and superior anterior pancreaticoduodenal, pyloric vein, and portal vein in the superior mesenteric vein-portal vein shunt reestablish the interrupted superior mesenteric and portal vein pathway (the occluded end of the superior mesenteric vein) (Vukojevic et al., 2018