For multi-use, bacteriostatic water is essential
If you have been vegan for several years without consistent B12 fortification, a GP blood test is the sensible starting point
How Soon May I Feel Results After Starting Vitamin B12 Injection Dosage For Adults
Schell JC, Wisidagama DR, Bensard C, Zhao H, Wei P, Tanner J, Flores A, Mohlman J, Sorensen LK, Earl CS, Olson KA, Miao R, Waller TC, Delker D, Kanth P, Jiang L, DeBerardinis RJ, Bronner MP, Li DY, Cox JE, Christofk HR, Lowry WE, Thummel CS, Rutter J., "Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism", Nature Cell Biology 19: 1027-1036 (2017)
Weeks 24: Metabolism Support Starts to Feel Real This is when people often begin noticing changes that support weight-loss progress