Specific situations requiring medical review include: Severe or persistent gastrointestinal side effects from Mounjaro that significantly limit your food intake for more than a few days You are taking metformin in addition to Mounjaro, as this combination increases B12 deficiency risk You have a history of pernicious anaemia, gastric surgery, or conditions affecting nutrient absorption You are considering stopping B12 injections whilst taking Mounjaro You experience any unexplained neurological symptoms Urgent medical attention is needed if you develop severe, persistent abdominal pain (which may radiate to the back), persistent vomiting, fever, or yellowing of the skin/eyes, as these could indicate pancreatitis or gallbladder problems Your GP or practice nurse can arrange blood tests to check your B12 levels (serum B12, holotranscobalamin, and if borderline, methylmalonic acid levels may be used where available) and determine the appropriate frequency of B12 injections if deficiency is confirmed

The injections also assist in detoxifying and improving liver function, which is essential for effective fat metabolism
Stay hydrated: Drinking plenty of water helps digestion and prevents constipation
Improvements can be immediate or take several days/weeks and last from days to weeks based on the individual and vitamin cocktail used