What are the benefits of B12 injection? Blades Wellness How Vitamin B12 Injections Impact Weight Loss Side Effects AlabamaAgeline.gov BENEFITS OF HAVING VITAMIN B12 INJECTIONS Vitamin B12 injection benefits include a healthier cardiovascular system, and for this reason we always recommend a course of treatments to individuals who are looking to Taking Vitamin B12? Read this first. While B12 is often hailed as a safe energy and brain booster, many real users are reporting unexpected side effects including anxiety, insomnia, Vitamin B12 Injection Side Effects and Safety Vitamin B12 Deficiency: Causes, Symptoms, and Treatment