HCG injections are totally different to B12 injections. HCG is a growth hormone, while vit B12 is a vitamin that prevents so-called pernicious anaemia. There is no proof that HCG injections promote weightloss in adults and such injections can in fact be most harmful. Please do NOT start using these injections. HCG stands for Human Chorionic Gonadotropin Hormone, and medications for the replacement of HCG are available with a doctor's prescription. They are usually used for women who are struggling to fall pregnant and men who need to increase their sperm count. The use of HCG injections together with the so-called HCG diet is highly controversial. Seeing that this diet only contains 500 kcal anyone will lose weight on it even if they don't have the injections. Submitting to HCG injections without a medical reason (. a low sperm count) is very risky and may cause all kinds of unwanted side-effects. I think you should rather stick to a health low-fat diet and daily exercise to lose weight.