Robert Huskinson, an attorney in Los Angeles, believes he's found the secret to looking and feeling younger. It's human growth hormone (HGH), which he's been taking for four years.

"I think it reverses the aging clock," asserts the 65-year-old Huskinson. "When I started taking HGH, my body composition changed. I burned fat and put on muscle tissue. I slept better and more soundly. My vision and hearing improved. I can lift more weight at the gym. It increased my testosterone level, which means I am more sexual than before. And my barber is astounded at how fast my hair grows."

HGH is a growth hormone secreted by the pituitary gland that diminishes with age. Because HGH affects protein, glucose, fat and carbohydrate metabolism, when HGH levels decline below normal, the results can include increased body fat, increased dehydration, wrinkles, impaired vision, poor memory, insulin resistance, low libido and loss of lean muscle mass.

Although Huskinson's blood tests showed that he wasn't deficient in the hormone for his age, he decided to take it — without knowing the long-term side effects.

"I am 65, and it could take 15 years before the entire medical community agrees on this. I'd rather take my chances," says Huskinson, who spends $1,000 a month on HGH. He injects himself with the hormone twice, sometimes three times daily and plans to do it for the rest of his life. (The Food and Drug Administration has approved only one form of HGH, an injectible drug available by prescription only).

Dr. Karlis Ullis, an anti-aging physician in Los Angeles and the author of Age Right, has prescribed HGH for about 500 patients, including Huskinson, over the past five years. But he's not convinced that HGH is the fountain of youth.

"I am a proponent of [HGH] in general, but it is not the magic answer that people thought it was. It is not a big gun in anti-aging, and it is overrated," says Ullis.

After taking the hormone himself for 18 months, Ullis now believes other supplements and lifestyle changes can produce the same results — and for far less money. A year's supply of the hormone will run you about $5,000.

"I think people are wasting their money on HGH," says Ullis. "You can get more HGH from exercise and sleeping better if you take melatonin or amino acids before you go to bed. Caloric restriction could also elevate HGH over time because calorie deprivation turns on growth factors in the body," says Ullis.