If you have a temporary deficiency or increased requirement (say, after a surgery or during recovery from an acute illness), you might only need a short course, perhaps a few weeks of injections, until your vitamin levels normalize or you can meet your needs by mouth again
Each patient's plan is tailored to their unique health goals while promoting patient safety
These typically resolve within 2-3 weeks
But despite their frequent comparison, they are fundamentally different compounds with distinct mechanisms of action
If you are low or deficient in B12, restoring healthy levels may improve fatigue and energy over time
For localized injuries (tendons, joints, surgical sites): Inject as close to the target tissue as practical