can you drink alcohol while taking b12 injection for Hangover: The Best Way To Take Vitamin B12 Sublingual B12 vs. B12 Injections:

Bacteriostatic water is commonly used in peptide reconstitution, but it is not appropriate for every person, compound, or route of administration

doi:10.1086/321262 Reynolds EH

What does a B12 injection do that a tablet cant

Doctors often recommend it as part of long-term therapy for patients who have absorption problems or cannot maintain sufficient B12 through diet alone

127 Another clinical trial in 50 patients with tinnitus, half of whom also had hearing loss, found treatment with intramuscular injections providing 100 mg vitamin B1, 100 mg vitamin B6, and 1,000 mcg vitamin B12 twice weekly led to tinnitus improvement mainly in those without hearing loss