do vitamin b12 injections cause constipation Are Shots Right for You? Vitamin B12 deficiency: Causes, symptoms,

It is best to use different injection sites now and then to minimize pain and inflammation

1 2 Annual Review of Nutrition

When to seek medical advice: Persistent or worsening injection site reactions (increasing redness, warmth, or discharge suggesting infection) Severe or persistent headaches Chest pain or palpitations Unexplained muscle weakness or cramps New or worsening neurological symptoms despite treatment Unexpected bleeding or bruising For non-emergency concerns, contact your GP or NHS 111

Treatments are usually administered over several weeks to gradually restore NAD+ levels while supporting metabolic balance