Big impact
Mild redness or tenderness at the injection site is possible but temporary
It is necessary for several aspects of health including formation of red blood cells, synthesis of DNA, energy production, heart health, brain function, and more

Food & Drug Administration (2025) Ozempic, DailyMed (2025) Wegovy, DailyMed (2024) Once-weekly semaglutide in adults with overweight or obesity, New England Journal of Medicine (2021) Vitamin B12, National Institutes of Health Office of Dietary Supplements (2024) Vitamin B12 injections: What they can and cant do, Cleveland Clinic (2024) Once-weekly semaglutide administered after laparoscopic sleeve gastrectomy: Effects on body weight, glycemic control, and measured nutritional metrics in Japanese patients having both obesity and type 2 diabetes, Obesity Pillars (2024) Inverse association between serum vitamin B12 concentration and obesity among adults in the United States, Frontiers in Endocrinology (Lausanne) (2019) Medically accurate: SingleCares Medical Review Board analyzes all of our content to confirm its in line with current medical advice

Most people absorb enough natural B12 that they dont have to worry about additional supplements, but for those with poor nutrition, stomach problems or cancer, B12 can be hard for the body to process