Many hormones are involved in the growth and development of humans. It is still not clear exactly how they all interact to produce a fully developed adult but the importance of Human Growth Hormone (hGH) is known to be great. HGH is produced in the pituitary and it releases growth promoting factors, collectively called somatomedins, from the liver and other tissues. Somatomedin C increases cartilage production in the long bones mainly at the epiphyses.

Hollywood movie star Sylvester Stallone is back on the big screen playing a bulked-up Rambo – and isn't afraid to talk about what helped him get in fighting shape. Sylvester Stallone admits he used Human Growth Hormone (HGH) to improve the appearance of his body for his latest Rambo movie, and does not think it was wrong to do so.

In an interview with Time magazine, the actor says HGH is not a steroid and defends its use.

The 61-year-old star tells that he pumped up to 209 lbs. with the help of prescription testosterone.