how do you feel after b12 injection Why I Worse My Injection? Understanding Post-Injecti – Oxford Origins Why Do I Feel Worse

The drug comes in several strengths, ranging from 2.5 milligrams (mg) to 15 mg

Also for people with circulation issues

Chickenpox and measles, for example, can have a more serious or even fatal course in children on immunosuppressant corticosteroids

First described back in the 1950s, acne erupts in about one in ten people within days or even hours of getting an injection of vitamin B12, which then disappears rapidly when injection treatment is discontinued. At the time, we had no idea what the mechanism might be, and the problem remained unsolved until just a few years ago when we finally figured it out: Vitamin B12 modulates the gene expression of the skin bacteria that cause acne

Circ Res 103:12321240