Please follow the aftercare advice for intramuscular Vitamin B12 injection:

• You may experience some mild tenderness, redness and swelling around the injection site. These effects will usually resolve within 48 hours but may last longer in some cases.
• You may experience some bruising around the injection site, this will resolve naturally but may take 1-2 weeks to resolve.
• If you experience any discomfort afterwards you can take a simple over the counter painkiller such as paracetamol.
• You must seek medical attention and contact your practitioner if you develop any signs or symptoms of skin infection around the injection site. Infection can present as hot, red shiny skin, there may be pus formation and you may have a fever or feel generally unwell.
• You must contact your practitioner as soon as possible if you experience any other unwanted side effects after having the injection.
• Seek medical attention if you feel unwell or experience any significant side effects following the injection.
• Seek emergency medical attention in the rare event that you experience any severe allergy signs or features of anaphylaxis after the injection. These may include rash, facial swelling and breathing difficulties.

It is essential that you have read all of the information available. Please do let your practitioner know if you have any questions or if you do not understand any of the aftercare instructions provided below.