can a b12 injection make you tired I Feel All the Time. Do I Need Shot?: Shawn Veiseh, M.D.: Family Medicine Vitamin B12 Side Effects

Feeling fatigued or burned out Are practicing a vegetarian or vegan diet Have a history of anemia or low B12 levels Take medications like antacids or metformin Are in a weight loss program Experiencing brain fog or low mood Want to enhance energy before workouts, travel or events Since B12 is water-soluble your body will excrete what it doesnt use, making the injections generally well-tolerated and safe

Vitamin B12 injections are commonly recommended for patients who have difficulty absorbing this essential vitamin through diet or oral supplements alone

If you notice symptoms returning before your next scheduled injection, contact your GP to discuss whether more frequent dosing is needed

If you need help with complaining for FREE you can contact your local council or local Healthwatch team to find out about independent NHS complaints advocacy services in your area

Retrieved 11 February 2026