b12 sublingual vs injection Injections vs. Oral Supplements: Which Is Better? is sublingual b12 as effective

Cochrane Handbook for Systematic Reviews of Interventions: Cochrane Book Series

While the etiology of NTD is multifactorial, some studies have found that blood concentrations of homocysteine or holo-transcobalamin to be lower in NTD-affected infants and mothers compared to non-affected controls (reviewed in 59)

While rare, you may also experience not-so-fun side effects, or even a life threatening allergic reaction, from a B12 injection

Theres even early discussion in research circles about using peptides to help maintain weight loss after someone comes off a GLP-1 drug potentially preventing the common rebound weight gain