It exists in various different forms, including: cyanocobalamin, hydroxycobalamin, methylcobalamin and adenosylcobalamin, Cobalamin (Vitamin B12) cannot be produced by your body, so it must be obtained via diet and supplementation.
Sun et al., 2019)
Translational andrology and urology , 7 (Suppl 3), p.S348
Some patients transition to high-dose nasal sprays or sublingual forms after initial injection therapy
However, as a new approach to enhancing the stability of peptides specifically, and as a part of developing new technologies for the protection and delivery of peptides, the glycosylation strategy, by attaching a sugar moiety to the peptides, is now gaining more attention