It is difficult to self-inject in this spot, so usually a trained spouse, friend or healthcare professional is needed for a shot of B12 in your arm
For a lot of people, the change shows up somewhere in the first one to three days
"It is important to remember that alcohol isn't a benign substancedrinking too much is associated with a higher risk of most cancers, heart disease, high blood pressure and depression." Frequently Asked Questions How much water should you drink while drinking alcohol
Use sterile needles and medical-grade B12 solutions
If you are concerned about your weight or nutritional status, the most appropriate first step is to speak with your GP , who can arrange relevant blood tests, rule out underlying conditions, and refer you to appropriate NHS services
FDA Briefing Document: Pharmacy Compounding Advisory Committee (PCAC) Meeting