what happens if i don't have my b12 injection Vitamin shots: Uses, benefits, and side effects 3 monthly injections : r/B12_Deficiency

Here's the low down

Intramuscular (IM) B12 injections using hydroxocobalamin, the preferred licensed form in the UK are recommended when: Oral supplementation has failed to correct a documented deficiency The patient has difficulty adhering to daily oral regimens Serum B12 levels remain persistently low despite adequate oral dosing There is clinical evidence of neurological or haematological complications In line with BNF guidance, the standard IM regimen for confirmed deficiency without neurological involvement is a loading course of 1 mg hydroxocobalamin on alternate days for two weeks , followed by maintenance of 1 mg every three months

Not worth the risk.

The response is dependent on temperature conditions