US$ 26.22
where inject b12 to Vitamin Best Vitamin B12 Injection Sites:
Description
Unfortunately, the most common form of B12 in supplements and fortified foods is Cyanocobalamin which is not as effective as Methylcobalamin

A deficit of B vitamins, particularly B12, B1, and B6, affects nerve function

The procedure is quick and relatively painless

Blood clots: It may promote the formation of blood clots , which are dangerous as they can block blood flow to vital organs such as the brain or heart
SARS-CoV-2 variants of concern and variants under investigation in England, technical briefing 28 (PDF) (Briefing)

Cells that would have died continue functioning