Sylvester Stallone Admits Using HGH To Bulk Up For 'Rambo'

Sylvester Stallone in 'Rambo' Sylvester Stallone in 'Rambo'

Sylvester Stallone says he used human growth hormone to get buff for the new "Rambo" movie, and defends its use.

"HGH (human growth hormone) is nothing," the 61-year-old actor tells Time magazine in its Feb. 4 issue. "Anyone who calls it a steroid is grossly misinformed."

Because it is nearly undetectable, HGH has become a substance of great concern in major league baseball and other sports battling allegations of rampant doping.

"Testosterone to me is so important for a sense of well-being when you get older," he says. "Everyone over 40 years old would be wise to investigate it because it increases the quality of your life. Mark my words. In 10 years it will be over the counter."

Stallone directed and co-wrote the new "Rambo" movie, which took in over $18 million at the weekend box office – good for a second place finish behind box office champ “Meet the Spartans.”