Many of the manifestations of aging can be slowed down or reversed by increasing the levels of Human Growth Hormone. HGH injections are usually administered only under proper supervision. HGH therapy helps in reducing excess fat and wrinkling of the skin, while facilitating substantial increase in muscle mass. HGH injections are prescribed only for those who are at least 30 years of age. The average cost of HGH injections is $500 to $1,000.