In people whose vitamin B 12 deficiency is related to overgrowth of intestinal bacteria, treatment with oral antibiotics such as tetracycline (sold under several brand names) may stop bacterial overgrowth and allow the absorption of vitamin B 12 to return to normal
Effectiveness of delivery routesinjectable versus oral/nasal absorption, stability of formulation
Methyl-Lifes Active B12 product is one of the few that contains all three active forms of B12 (methylcobalamin, adenosylcobalamin, and hydroxocobalamin) in a sublingual tablet
If you do inject insulin into your muscles, it'll be used up much more quickly and potentially cause bruising
Published work on intranasal peptide delivery (for insulin analogs, calcitonin, and oxytocin) demonstrates that bioavailability for this size class without enhancers is typically in the low single-digit percent range, though these data are from different peptides with different charge profiles
