vitamin b12 injection im dose B-12 Cyanocobalamin
1000 mcg / mL Intramuscular or Subcutaneous
Multiple Vial 30 mL , Each
Westeard 00143961910 Vitamin B12 Cyanocobalamin 1,000 mcg

And it makes it very hard to to apply a blanket rule - some people may manage well with alcohol and injections

Any unused portion can be stored for later use for up to 60 days after initial opening instead of being discarded at the days end, as is the case with other injections

This type of injection provide the advantage of better bioavailability by avoiding enzymes in the gastrointestinal tract

"Effect of Vitamin B6, B9, and B12 Supplementation on Homocysteine Level and Cardiovascular Outcomes in Stroke Patients: A Meta-Analysis of Randomized Controlled Trials"

Compounding pharmacies recognized these patterns and began including B12 as a preventive measure