injectable b12 vs oral Vitamin Injections vs. Supplements: Which Works Best? Vitamin B12 Injections vs. Oral

Oral is the standard

The short answer is that for most people, B12 injections given in a medical setting have a strong safety record

Expectations and timeline Users typically report initial effects within the first two weeks of use

In contrast, DIO mice in both groups switched from WD to LD each had significantly increased Proteobacteria relative abundance (represented solely by the genus Parasutterella ) compared to both the WD and the LD controls, suggesting that Proteobacteria relative abundance may be largely influenced by stress or the differences in net energy expenditure (or associated body weight changes) caused by the diet switch