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 How Long Do B12 Injections Last: 5 Ways to Extend Effects Vitamin B12 Injections Energy Boost The Center Medical Methylcobalamin B12 Injection in Beverly Hills, Arcadia and Los Angeles County California Infusion Centers Vitamin B 12 Injection for Animals, 3000 mcg mL, 100 mL Vial Prescription Medication for Pets Are expired vitamin b12 syringes still effective?