Although some weight loss clinics claim that certain vitamin and supplement injections assist with weight loss, there is no concrete evidence to suggest that injections help people lose weight as of 2015. According to Mayo Clinic, some weight loss clinics administer vitamin B-12 shots because they act as a vitamin supplement. However, unless the individual suffers from a vitamin B-12 deficiency, the injection is not likely to assist with anything other than restoring balance to the person's immune system.
Mayo Clinic indicates that the restoration of proper B vitamin balance may give the individual a temporary energy boost, but the injection does not necessarily assist with weight loss. B vitamins are essential for maintaining proper health and nutrition, but they do not radically alter an individual's metabolism.
One non-vitamin injection that may prove successful as a weight loss aid is Saxenda. The drug's primary purpose is to help stabilize blood sugar levels in diabetics, and it is available as of November 2015 as an injection to assist with weight loss. On December 23, 2014, the Food and Drug Administration approved Saxenda as a weight loss injection safe for the public to use alongside a lower-calorie diet and exercise routine. WebMD reveals that more than 60 percent of people who received a daily injection of Saxenda in certain clinical trials lost at least 5 percent of their total weight. However, these injections also come with significant side effects, including nausea, vomiting, diarrhea, constipation and increased appetite.