what to expect after a b12 injection How Fast Do Injections Start Working? Feeling worse after B12 Injection:

Are you using it consistently (most days of the week)

Effects on frontal or vertex follicles (where hair loss actually occurs) may differ, though subsequent studies have confirmed activity in these regions

How long a B12 shot lasts depends on the form of B12 used in the injection, how severe your deficiency is, and how well your body absorbs the form thats being injected

Clinical Nutrition Open Science, 41, 100065

Yes, a vitamin B12 deficiency can be a contributing factor to hair loss in some individuals

Adequate red blood cells mean adequate oxygen delivery to muscles during exercise directly affecting physical performance and recovery