injectable b12 for humans Methylcobalamin 10,000mcg injectable, 10mL (lyophilized) Cyanocobalamin (Dodex): Uses, Side Effects,
Description
Molecular Weight: 286.11 g/mol (as iodide salt)

A compound that only raised plasma free fatty acids without increasing oxidation might simply be redistributing fat and raising cardiovascular-risk-associated lipids

So not only does the USA use the synthetic form which isn't as healthy and the body has to convert, they also include a dose of poison (aluminum)

For long-term storage, lyophilized peptides should be kept in the freezer

Its important to know the possible side effects, from mild injection site reactions to rare serious allergies