how to inject b12 self-inject intramuscular vitamin - Overview B12 Injection Dosage and Frequency:
Description
[DOI] [PMC free article] [PubMed] [Google Scholar] 16.Rudolphi B, Zapp B, Kraus NA, Ehebauer F, Kraus B, Kraus D

Metabolism 92, 7181

Each mL of solution contains 1000 mcg of cyanocobalamin, used to treat vitamin B deficiencies, particularly in cases of malabsorption such as pernicious anemia
There are some very rare side effects listed in medical literature (mostly when large doses are given): for example, one out of many thousands of patients might develop a disturbance in liver enzymes or a tingling in the fingers or toes