how does a b12 injection make you feel to Give Injection: Step-By-Step Instructions B12 Injection Services - Subtly
Description
This article points out the benefits of B12 injections and how long they can last

For best results, use regularly as part of a scalp care routine
The mechanism appears unrelated to the lipolytic pathway
Possible side effects may include mild pain or swelling at the injection site, headache, nausea, or anxiety
