There is After having a B12 shot, a person should monitor for adverse symptoms and seek medical help if they experience: severe pain at the injection site mild diarrhea a swelling sensation in the body temporary itching of the skin In rare cases, a person may also be at risk of: anaphylaxis pulmonary edema congestive heart failure peripheral vascular thrombosis, which involves blood clots polycythemia vera, which is a type of blood cancer If anyone experiences difficulty breathing, hives, or swelling, they need emergency medical help
As long as the color returns to a light yellow after you have had a glass or two of water, it is not a cause for concern
Platelet-rich Plasma (PRP) injections could be the treatment that works
Both are safe
No published study has demonstrated this, but the question remains open (Crockford et al., Ann N Y Acad Sci 2010)
2.5 mg is always 25 units