Lilly Says Compounded Tirzepatide With Added Vitamin B12 Contains Impurities. Is It Safe? The Feline Essentials B12 has definitely improved my cat's appetite and appearance in recovering from Pancreatitis. I started using the B12 last week in combination with the CATalyst product that I've been Hi I bought the B12 injectable liquid but there's no use by date on it or how long you have to use it once it's opened. Anyone know the answer? TIA x Calcium Gluconate and Vitamin D3 & B12 Injection Best Price for Animal Health Compounded Vitamin B Complex Injection Empower Pharmacy