Human growth hormone (HGH): Does it slow aging process?

Your body naturally makes growth hormone to help fuel growth during your childhood and to help maintain your tissues and organs throughout your life. Beginning in your 40s, your pituitary gland — the pea-sized structure at the base of your brain where growth hormone is made — slowly reduces the amount of the hormone it produces.

Some people believe the dwindling level of growth hormone is responsible for the frailty that typically comes with getting older. And that's prompted some who are concerned about growing old and losing independence to turn to injections of synthetic human growth hormone (HGH) to stave off the realities of old age. But there's little evidence to suggest human growth hormone is the Fountain of Youth.

What can human growth hormone do for healthy older adults who don't need it?

Studies of healthy older adults taking human growth hormone are limited. Many involve a small number of people followed for a short period of time. The studies that have been conducted have found that human growth hormone injections can increase muscle mass and reduce the amount of body fat in healthy older adults.

That increase in muscle doesn't translate into increased strength. Though the study participants gained muscle, they weren't any stronger. One study compared older men who took human growth hormone with older men who went through strength training programs. The bottom line: Strength training can increase both your muscle mass and your strength, making it cheaper and more effective than taking human growth hormone.

It isn't clear whether human growth hormone can provide other benefits, such as increased bone density and improved mood, to healthy adults. Most of the research into human growth hormone has focused on people with true growth hormone deficiencies.

Does human growth hormone come in pill form?

Some Web sites claim to sell a pill form of human growth hormone that produces results similar to the injected form of the drug. Sometimes these are called human growth hormone releasers. There's no proof that these claims are true. In fact, if you were to swallow human growth hormone, it would likely be digested by your stomach acids and not absorbed into your body.

Web sites also sell homeopathic remedies claiming to contain human growth hormone. There's no proof that these work, either.