b12 injection intramuscular or subcutaneous Injections at Home - Safety Guide for Self-Administration B12 Shots vs. IV Infusions:

Research suggests about 20 per cent of elderly people are B12 deficient

If your deficiency has caused neurological symptoms, that loading phase can run longer before maintenance begins

Note: While B12 is sometimes marketed as an energy booster, strong evidence of benefit in individuals with normal B12 levels is limited

Other studies showed that those who had both antidepressants and vitamin B12 were more likely to demonstrate an improvement in their symptoms

Its not for human consumption, nor is it intended to diagnose, treat, cure, or prevent any disease

NHS support for home administration: Most GP practices offer training sessions where practice nurses demonstrate proper injection technique, sharps disposal, and emergency procedures