How Long Does A B12 Shot Last? Affecting Factors of B12 Injection Feeling run down, low on energy, or struggling to focus? Our latest blog explains how a Vitamin B12 Injection Consultation works and what to expect. You'll receive professional, face to face care in our Feeling tired, foggy, or run down? It could be a B12 deficiency Weekly B12 injections help support: Increased energy + reduced fatigue Sharper focus + better mood Boosted Always Tired? B12 Injections Could Help B12 Injection Dosage and Frequency: 7 Essential Guidelines for Adults Liv Hospital