NSI® Natural GH Formula contains the optimal levels and combination of key nutrients that may stimulate growth hormone release. As we age, the hormones we need to stay healthy decline. One of the most important hormones is the growth hormone (GH), also known as human growth hormone (HGH). Growth hormone plays a role in body composition (lean muscle), energy levels, cholesterol levels, immune function, and sexual performance. Certain nutrients may stimulate the natural release of GH in many people, including niacin (vitamin B3), and particularly amino acids, including L-arginine, L-lysine, L-glutamine, L-ornithine and L-glycine. Did You Know? All NSI supplements are packaged in HDPE (High Density Polyethylene) bottles. These bottles keep moisture vapor out, protecting the freshness and integrity of their contents, and are 400% more effective compared other brands currently using PET (Polyethylene Terephthalate) bottles. HDPE bottles do not break as glass can and are also recyclable so we urge you to please recycle them.