Does human growth hormone slow the aging process?

Can HGH prevent dreaded old age? See more healthy aging pictures.
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­When Juan Ponce de Leon set sail off the coast of Spain in the 1500s, he was in search of the Fountain of Youth. He didn't find it. Instead, he found Florida, where he eventually was shot dead with arrows by angry Native Americans. Not exactly the everlasting youth he'd hoped for.

But just because Ponce de Leon failed to find the Fountain of Youth doesn't mean we've stopped searching for it. In fact, the quest for eternal youth is timeless. More than 500 years later, we're still trying to turn back our bodies' clocks. We inject our faces with poison, get fat vacuumed out, swallow vitamin supplements -- anything to remove the signs of aging and thumb our noses at the Grim Reaper.


In fact, nowadays there are some people who believe they've found youth's fountain -- a hormone that helps you to lose weight, reduces wrinkles, lowers blood pressure, adds muscle mass, increases energy and actually reverses the aging process. It sounds like a fantasy, but it's actually something our bodies create naturally -- human growth hormone (HGH).

HGH is a hormone produced by the pituitary gland, a pea-sized gland found at the base of the brain. The pituitary gland produces various hormones, and each affect a specific part of the body. The human growth hormone targets muscles and bones, and the pituitary gland produces the most HGH during adolescence. HGH is essential for normal growth. For example, if a child's body produces too little HGH, the child may end up being very small in stature. Conversely, if a child's body produces an excess of HGH, he or she may experience exaggerated bone growth and become exceptionally tall. Both scenarios may result in medical problems.

­Even after we grow up, our bodies continue to produce HGH. It plays an important role in regulating our metabolism. We generate it as we sleep, which is part of the reason why getting enough sleep is so important for our health. Production of HGH begins to decrease markedly around age 30 and slows progressively as we age further.

HGH is what gives us our youth, vitality and strength. Without it, well, we get old. Aging is inevitable, but many people aren't willing accept that fate without putting up a fight. Could HGH pack the final punch? Let's find out.


Effects of Aging on the Body

­From birth all the way to death, our bodies are constantly changing. Let's take a look at what happens as we age. When you have a normally functioning pituitary gland, human growth hormone (HGH) contributes to these processes.

As soon as we're born, we start developing our muscle strength and nervous system. One of the first things we learn to do as babies is focus our eyes. By the age of two, our vocabulary begins taking shape. As toddlers and children, we begin developing finer muscle control and motor skills. Later, puberty causes quick growth and hormonal changes. As we move into adulthood, we stop growing and reach physical maturity. We have HGH to thank for most of these developments.


In our 30s and early 40s, the level of HGH in our bodies begins to decline. Our metabolism slows, causing the "middle-aged spread" that so many people try to avoid. Between the ages of 40 and 65, we see our muscle strength decline, along with our vision and hearing. Our late 50s to early 60s may bring some cognitive decay as well.

Moving into our late 60s and beyond, our skin becomes less elastic. Our joints and bones may become brittle. Medical conditions like heart disease or cancer become more likely as our bodies are unable to repair themselves the way they used to. At this point, the levels of HGH in our bodies are only one-fifth or less of what they were during youth.

Proponents of HGH claim that the hormone can help decline or even reverse this aging process. They say that raising the HGH levels in their bodies has helped them with everything from weight loss to undoing damage from congestive heart failure [source: DeSimone]. Next, we'll see what the medical community thinks.


Traditional Uses for Human Growth Hormone Treatment

Even though we mostly hear about human growth hormone (HGH) treatment in the context of controversy, it does have legitimate medical uses. Growth hormone deficiency (GHD) is a disorder that can occur in both children and adults.

Children with GHD may grow less than 2 inches (5 centimeters) per year, an indication that there is something amiss with their levels of HGH. The child's blood sugar may be lower than normal, and sexual maturity is delayed. An endocrinologist usually makes a final diagnosis. Some adults can develop GHD after reaching physical maturity, or if their pituitary gland is damaged by something like trauma or radiation treatment. Symptoms include increased body fat, decreased muscle and bone mass, low energy levels and poor sleep. It's important to note that these symptoms must come from a true hormone deficiency and not simply the natural loss of HGH that goes with the aging process. Again, an endocrinologist can run tests to determine if a deficiency is, in fact, the problem.


­HGH is a valuable treatment for growth hormone deficiency. Daily injections improve symptoms in both children and adults with GHD. It's important to note that HGH is only effective if delivered via injection. Stomach acids will break it down if ingested, so an injection delivers it directly to the bloodstream. The injection also allows the greatest concentration of HGH to enter the body. Pills, sprays or powders have little or no effect on the body.

Human growth hormone is also effective in treating muscle weakness related to HIV or AIDS. Its success with healing muscle damage is one of the reasons athletes tend to take injections of HGH, even though it's a banned substance in sports. Many trainers believe it greatly speeds up the healing process for torn muscles and surgery [source: Reynolds].

Next, we'll take a look at the medical study that launched a thousand e-mail marketing ploys.


The Study on HGH and Aging

­In 1990, the New England Journal of Medicine published a small-scale study of human growth hormone (HGH). In a trial, researchers injected a dozen healthy men, age 61 to 81, with HGH for six months. The study showed amazing results. The men reported an increase of lean body mass, a decrease of body fat, increased elasticity of skin, improved mood and positive increases in blood pressure and blood sugar. It even appeared that organs like the heart and kidneys actually began returning to normal size (our vital organs tend to shrink with age). The study seemed to point to HGH as a miracle drug in combating the effects of aging.

Using these findings as a jumping-off point, researchers hypothesized all sorts of ways HGH could help the elderly. Patients recovering from broken hips or other bone-related surgery might heal faster. Bedridden patients with loss of muscle could use HGH to help rebuild what had wasted away. The possibilities were endless, and when the study hit the news media, a wave of excitement rippled through the health and nutrition community.


However, editors of the journal stressed that further studies were necessary. First of all, the study didn't include women, so there was no way of knowing if the female body would react to the injections in the same manner. Also, the men were only injected for six months. There were no studies on the long-term effects or overuse of the hormone on a man's body. The researchers also admitted that just because the men's organs and muscles grew bigger, there was no proof that they were more powerful or healthy.

The New England Journal of Medicine amended the article with an editorial statement that read: "Our understanding of growth hormone, its interrelations with other hormones, and its regulation of metabolism is considerable. Although its actions and benefits are fairly clear in children with growth hormone deficiency, they are not at all clear in adults" [source: Vance].

However, that one study was all some fraudulent advertisers needed. Soon, online retailers were selling HGH in all different forms. Today, scams citing the 1990 study as their medical proof are everywhere. In 2003, the Journal was also forced to add a note to its study denouncing these various misleading advertisements.

Read on to learn about HGH controversies and side effects.


HGH Controversies

Andy Pettitte of the New York Yankees speaks to the media during a press conference to discuss his HGH use. 
Rovert Browman/Stringer/Getty Images


Today, more than two decades since mass-produced human growth hormone (HGH) became available, it's still not proven to slow or reverse the aging process. This is especially true for those under the ages of 40 or 50. Until this age, our bodies are still producing HGH. Adding extra HGH to our bodies likely doesn't do much. And although it's true that some studies have shown that HGH promotes lean muscle growth and reduction of body fat in older people, the studies haven't shown a corresponding increase in strength or endurance [source: Interlandi].


Even though no formal research exists to prove definitely that HGH works as antiaging therapy, you can find informal testimonials all over the place. Hopeful patients -- men and women, young and old -- all over the country pay upward of $15,000 per year for monthly injections of HGH. Many of these patients insist that the injections restore their youthful vigor, energy and health, as well as diminish wrinkles and improve their skin [source:­Kuczynski]. However -- and this is a biggie -- using HGH for antiaging purposes is illegal. To receive a prescription for HGH therapy, you must have proof via a blood test that your hormone levels are deficient. Many doctors prescribe the hormone for antiaging anyway but are seldom prosecuted [source: Hellerman]. It's also against the law to use HGH without a doctor's supervision, rendering most online sales of the hormone illegal.

An online search for "buy HGH" yields more than a quarter-million hits. However, the Federal Trade Commission (FTC) warns consumers that there is no reliable evidence to support any claims that HGH can turn back the hands of time, help you to lose weight instantly or grow bigger muscles. Many of these marketers sell their HGH in the form of pills, sprays or powders. As we talked about before, the only effective way for your body to process HGH is through an injection. Also, the FTC warns against any company that sells products claiming to boost your body's HGH production [source: Better Business Bureau].

There may be no proof that HGH is a fountain of youth, but there is plenty of proof that HGH can cause some serious side effects. Healthy adults who take HGH could develop any of the following:

  • Swelling in the arms and legs
  • Joint pain
  • Abnormal bone growth
  • Muscle pain
  • High blood pressure
  • Edema
  • Arthritis
  • Diabetes
  • Carpal tunnel syndrome
  • Enlargement of breast tissue.

Some doctors are even afraid that overuse of HGH could lead to cancer [source: Zarda].

So, after all this, you're probably still wondering whether or not HGH slows the aging process. The answer? There's no concrete scientific proof yet that it does. What does stave off aging? A regimen of eating healthy, reducing stress and getting lots of exercise.

For more about HGH and aging, check out the links on the next page.


Lots More Information

Related HowStuffWorks Articles


  • Angier, Natalie. "Human Growth Hormone Reverses Effects of Aging." New York Times. July 5, 1990. (March 13, 2009)
  • BBC News. "Human growth hormone." June 23, 1998. (March 13, 2009)
  • Better Business Bureau. "FTC - 'HGH' Pills and Sprays: Human Growth Hype?" June 1, 2005. (March 13, 2009)
  • Celizic, Mike. "Sylvester Stallone discusses HGH charge." Jan. 18, 2008. (March 13, 2009)
  • Chapman, MBBS and Ph.D., Ian M. "Introduction: Pituitary Gland Disorders." Merck Manual Home Edition. February 2007. (March 13, 2009)
  • CNN Health. "Effects of Aging on Your Body." August 14, 2007. (March 13, 2009)
  • DeSimone, Bonnie. "REMEDIES; Growth Hormone: The Secret of Youth or a Cautionary Tale?" New York Times. April 11, 2006. (March 13, 2009)
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  • Kuczynski, Alex. "Anti-Aging Potion or Poison?" New York Times. April 12, 1998. (March 13, 2009)
  • Mayo Clinic. "Human Growth Hormone (HGH): Does it slow aging?" Feb. 21, 2009. (March 13, 2009)
  • Merck Manual of Health & Aging. "Dietary Supplements." 2009. (March 13, 2009)
  • Reynolds, Gretchen. "Raging Hormones." New York Times. August 20, 2006. (March 13, 2009)
  • Vance, MD, Mary Lee. "Growth hormone for the elderly?" The New England Journal of Medicine. July 5, 1990. (March 13, 2009)
  • White, David. "Ponce de Leon and the Fountain of Youth." Social Studies for Kids. 2009. (March 13, 2009)
  • Zarda, Brett. "Does HGH Make Men Stronger and Women Hotter?" Popular Science. Feb. 20, 2008. (March 13, 2009)