had b12 injection but still tired Are Vitamin Shots Right for You? Feeling worse after B12 Injection:

If patients dont maintain a healthy lifestyle results will not be permanent

Although the body typically has sufficient vitamin B 12 stores to last 3-5 years, once PA has been established the lack of absorption of new vitamin B 12 is compounded by the loss of the vitamin because of negative balance

Mitochondrial protein interactome elucidated by chemical cross-linking mass spectrometry

However, for those who have dietary restrictions or absorption issues, supplements are often necessary to meet the required intake

Rare adverse effects specific to cyanocobalamin may include mild transient diarrhea, particularly with initial doses, and very rarely, allergic reactions in sensitive individuals