vitamin b12 injection cycle B12: A Review of Clinical Use and Efficacy What is Vitamin B12? -
Description
They can for some people

Several factors influence the price of this treatment

Redness and swelling may occur, and the area may be painful for a few hours
Since nitrous oxide is commonly used for surgery in the elderly, some experts feel vitamin B 12 deficiency should be ruled out prior to its use or prophylactic vitamin B 12 supplementation implemented before and after exposure to the gas (7, 18)

For a practical injection checklist and tips see this injection guide: Vitamin B12 injection guide