Human Growth Hormone is essential for bone and organ growth in our youth. HGH is produced at a rate that peaks during adolescence, at time when normal growth is accelerated. The production of human growth hormone decreases with age, 14% each year on average. Humans normally produce about 500 micrograms of growth hormone daily at age 20. By age 80, the daily production falls to 60 (or less) micrograms. Many doctors consider IGF-1 levels sub 350 to be HGH deficient.