Buy Human Growth Hormone (or HGH) is a hormone that stimulates growth, cellular reproduction and renewal, in both humans and animals. HGH is produced in the pituitary gland, and is a natural way of regulating growth, fat metabolism and sugar levels in humans. HGH works in conjunction with collagen (a protein that makes up nearly 30% of the protein content in the human body) to maintain the bodies skin and muscle composition. The trouble is, as you get older, your body will produce less HGH and collagen. This is where HGH supplements come in, by boosting your bodies HGH levels.