do vitamin b12 injection go bad How Quickly Does Shot Work? Does It Help to Lose Weight? B12 injection & Acne -
Description
So the typical pattern is a short loading phase of weekly shots to refill the tank, followed by a maintenance injection every few weeks to a month to keep levels steady

Liblau, et al
Oral supplements, such as B12-fortified foods or vitamin B12 supplements, may also be used to treat vitamin B12 deficiency

The proposed mechanism centers on activation of a beta-3 adrenergic-like pathway in adipocytes rather than via the canonical hGH receptor