does vitamin b12 injection cause sleepiness Why do I feel worse after a injection? Feeling worse after B12 Injection:

Potential Risks and Precautions Though B12 injections are generally safe when administered correctly, there are potential risks including bruising, infection, or allergic reactions

Research has confirmed no significant effects on serum IGF-1 levels, no negative effect on carbohydrate metabolism, and no immunogenicity with no anti-AOD-9604 antibodies detected in any participants

Proceedings of the Nutrition Society 74

Amounts of vitamin B 12 that are recommended by the Food and Nutrition Board, National Academy of Science-National Research Council for pregnant women (4 mcg daily) should be consumed during pregnancy

Tsai I-C et al