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 February 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 cowrote the new Rambo movie, which arrived in theaters Thursday.