how long do the side effects of b12 injections last Why I Feel Worse After My Injection? Causes & Management – Bolt Pharmacy How Long Does It Take

They have been developed so that the active substance is stable and well-absorbed from the digestive tract, eliminating the need for injections

IM Injection Protocols for Pernicious Anemia Intramuscular (IM) shots are a common way to give vitamin B12 to those with pernicious anemia

Rotate injection sites to prevent tissue damage and maintain optimal absorption

While the effects of a vitamin B12 injected will become noticeable around 24 hours after administration, they will start to take effect almost immediately and will stay in your system for around 1 week, but may vary depending on the metabolic rate of the patient