B12 shots offer a range of benefits, including increased energy levels, improved metabolism, reduced fatigue, sharper concentration, enhanced sleep patterns, mood elevation, and a strengthened immune system
NZMJ 10:1436 Tuba-Kartal A, ala-Mutlu Z (2020) Comparison of sublingual and intramuscular administration of vitamin B12 for the treatment of vitamin B12 deficiency in children
In some cases, blood clots have occurred (again, this is typically with a very high dosage, and it is possibly a complication of other medical conditions, or other medications which interact adversely with the B12)
specific formulations vary by pharmacy and prescriber order