Growth hormone is primarily produced and secreted by the pituitary gland. Once released, growth hormone triggers the liver to release an enzyme called IGF-1 (Insulin Like Growth Factor – 1). IGF-1 enters the body cells and stimulates lipolysis, or the conversion of fat into energy.
The exact mechanism of action of growth hormone is not 100% understood, however, we do know that it does not act directly on the cellular tissue it is “telling” to grow. Rather, it stimulates the liver and other organs to produce and release another hormone known as insulin-like growth factor 1, or IGF-1. IGF-1, and similar compounds are the chemical messengers that actually cause cells to divide and tissues to grow.