Two years ago, Richard Casey was feeling his age. At 48, he was tired, gaining weight and suffering from a growing number of aches and pains. On top of that, his libido had decreased.
"I could see the distance between my 40s and my 20s," he says. "As I looked ahead, it was all downhill. That's depressing."
Looking for relief, he found a Chicago doctor named Paul Savage, who focuses on adjusting hormone levels in older patients. Savage modified Casey's diet and workout, and prescribed several hormones, including human growth hormone.
Since then, Casey's physical condition has improved significantly. He says he has lost fat, added muscle, feels more lively, and has a stronger sex drive. He is convinced growth hormone played a key role.
"It gives you the feeling of a more hopeful tomorrow," says Casey, a computer executive in Parsippany, N.J. "I get up in the morning, I'm alert, and I have steady energy through the day."
Long used to help very short children catch up to their peers, growth hormone has gained recent notoriety as a drug of abuse among elite athletes. Baseball superstar Barry Bonds allegedly injected it regularly, as did Olympic sprinter Ben Johnson. Users believe it boosts strength and endurance.
But more and more, another group is taking growth hormone - aging but relatively healthy people who hope to improve the quality, and perhaps the length, of their lives. Patients such as Casey say growth hormone helps make them feel decades younger, with few, if any, side effects.
Some practitioners have turned the promise of hormonal rejuvenation into a booming business. Savage, for example, has opened seven clinics around the country, all focusing on people concerned about low hormone levels.
But skeptics say using growth hormone to battle aging is unproven, potentially dangerous and illegal. They say proponents are taking advantage of baby boomers' unrealistic desire to permanently stave off aging.
"There's no science behind it. It's all marketing, in my opinion," says Boston University geriatrics professor Dr. Thomas Perls, a leading critic.
Scientists discovered human growth hormone in 1956. Twenty years ago, researchers devised a method to create it synthetically - before that the substance was only available by harvesting it from cadavers.
Because the gastrointestinal tract breaks down the growth hormone molecule, users can't take the drug by mouth - it must be injected. About a half-dozen drug companies make growth hormone, which is legally available only by prescription.
Growth hormone acts as a kind of master switch for other hormones, including testosterone, estrogen and Insulin-like Growth Factor-1. Studies show that the substance can increase growth of bone, muscle and other tissues.
"Growth hormone is a potentiator of other hormones," says Los Angeles physician Mark Gordon, who has been prescribing it to adults for eight years. So far, Gordon has opened clinics in Los Angeles and Phoenix, as well as two in Russia.
At first, the substance was used primarily to treat children who were extremely short because of a growth hormone deficiency. As the name implies, it can often trigger a growth spurt, enabling patients to reach normal height.
But during the past decade, growth hormone has increasingly been used by athletes, as well as other adults who want to look and feel better.
It is difficult to estimate the number of users, particularly because many doctors who prescribe it, and patients who take it, are wary of publicity. But leading proponents estimate that 50,000 to 100,000 healthy adults in this country now use growth hormone.
`Quality of life'
Supporters say the practice makes good medical sense. They note that between the ages of 20 and 60, growth hormone levels typically drop by 50 percent to 65 percent. Replacing this lost production, they say, can significantly improve health.
"Growth hormone is integral to quality of life, and it may affect quantity of life," says Chicago physician Ronald Klatz, a leading practitioner of what is sometimes called anti-aging medicine.
Another believer is Dr. Alan Mintz, founder of the Cenegenics Medical Institute in Las Vegas. Originally a radiologist, Mintz made millions from a medical management company, then sold that firm and started Cenegenics, which has clinics in Hong Kong; Seoul, South Korea; Tokyo; and Charleston, S.C.
Cenegenics patients pay $2,000 for a seven-hour evaluation, followed by a comprehensive set of dietary and exercise recommendations. Most also begin a course of hormone therapy.
Mintz, 67, says he's taken hormones, including growth hormone, for decades. Until recently he was a competitive bodybuilder.
Another Cenegenics doctor is Jeffry Life, who has been taking growth hormone since 2003.
A serious weight lifter, the 67-year-old began injecting himself after noticing that he was losing strength. He says his bench press subsequently improved from 195 pounds to 260 pounds.