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Human Growth Hormone (HGH) and Adult Growth Hormone Deficiency

HGH Human Growth Hormone

Growth hormone (GH or hGH) is a small protein that is made by the pituitary gland and secreted into the bloodstream. GH production is controlled by a complex set of hormones produced in the hypothalamus of the brain and in the intestinal tract and pancreas.

The pituitary puts out GH in bursts; levels rise following exercise, trauma, and sleep. Under normal conditions, more GH is produced at night than during the day. This physiology is complex, but at a minimum, it tells us that sporadic blood tests to measure GH levels are meaningless since high and low levels alternate throughout the day. But scientists who carefully measure overall GH production report that it rises during childhood, peaks during puberty, and declines from middle age onward.

GH acts on many tissues throughout the body. In children and adolescents, it stimulates the growth of bone and cartilage. In people of all ages, GH boosts protein production, promotes the utilization of fat, interferes with the action of insulin, and raises blood sugar levels. GH also raises levels of insulin-like growth factor-1 (IGF-1).

It is normal for GH levels to decline as a person reaches adulthood, but new research suggests that some adults may have too low a level. Low levels of GH are linked to poor immune system, poor muscle tone, increase body fat, low energy levels, and cardiovascular changes, cholesterol and memory issues. GH insufficiency is associated with pituitary gland problems, brain injury, autoimmune disorders, and nervous system conditions.

Synthetic human growth hormone was developed in 1985.  Growth hormone, also known as somatotropin or somatropin, is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. It is a type of mitogen which is specific only to certain kinds of cells. Growth hormone is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by somatotropic cells within the lateral wings of the anterior pituitary gland. Growth hormone is not a steroid as many media outlets suggest. Growth Hormone works as a “repair” hormone. To take full advantage of HGH, balance and correct your other hormones first.

A better term for GH would be healing or repair hormone. Growth hormone is naturally produced by our pituitary gland and is essential for bone and organ growth in our youth. Although hGH is no longer needed for growth after reaching adulthood, hGH is essential for many other vital functions, and the significantly lowered levels seen as we age are correlated with everything from diminished energy, cardiovascular disease, increased body fat, decreased muscle mass, and more.

Growth hormone diminishes rapidly after the age of 30. It is found that growth hormone deficient patients have almost 50% higher rate of death from heart disease than those with more optimal levels. In a 1990 New England Journal of Medicine article, Dr. Rudman reported on his study with the use of human growth hormone in elderly veterans.

“The effects of six months of human growth hormone on lean body mass and adipose tissue reversed the equivalent of changes incurred during 10-20 years of aging. The overall deterioration of the body that comes with growing old is not inevitable…We now realize that some aspects of it can be prevented or reversed.” – Dr. Daniel Rudman, MD – New England Journal of Medicine

In 1999, the National Institute on Aging completed another landmark study that was designed to either refute or substantiate the results of Dr. Rudman and to extend his study by measuring other parameters. This was a double-blind, placebo-controlled, multi-center trial in both men and women with many patients. This study involved not only growth hormone but also the estrogen, progesterone and testosterone. This study not only confirmed the benefits of growth hormone, but also demonstrated that the addition of estrogen/progesterone and testosterone improved the effectiveness of growth hormone.

After 6 months treatment of 0.75 I.U./day here are the percent of patients reporting improvement in different areas. (Results may vary.)

Physical Signs of HGH Treatment

  • Less wrinkles on face (75.5%)
  • Less sagging skin on face and neck (67%)
  • Firmer muscles (60.7%)
  • Less body fat (48%)
  • Better skin (thicker) (34.5%)
  • Thicker head hair (28.1%)>

Emotional/Mental Improvements of HGH Therapy

  • Improved emotional state (71.4%)
  • Increased energy (86.8%)
  • Improved physical stamina (86.04%)
  • Increased ability to stay up late (82.5%)
  • Improved resistance to stress ((83.7%)
  • Significantly decreased Anxiety (calmer) (73.5%)
  • Improved assertiveness (73.1%)
  • Improved sense of power (77.8%)
  • Improved self-esteem (50%)
  • Depression improved or eliminated (82.7%)
  • Improved sociability (77.8%)
  • Decreased tendency to give sharp verbal retorts (71.0%)

This study and numerous others demonstrate that treatment with growth hormone results in significant improvements in both physical appearance and in emotional and mental well-being. The enhancement in quality-of-life with the use of growth hormone is truly remarkable.

The FDA has approved hGH for adult deficiency after being the most scrutinized pharmaceutical in history. After many years of research and clinical use, growth hormone has proven to have an excellent long and short-term safety profile with almost no side effects.


In a 1990 study published in the New England Journal of Medicine, the administration of human growth hormone for six months was accompanied by an 8.8 % increase in lean body mass, a 14.4 % decrease in adipose-tissue mass, and a 23.2% improvement in overall body composition. There was a 1.6% increase in average lumbar vertebral bone density, and skin was transformed into a much more youthful appearance with significantly less wrinkles and increased thickness of 7.1 percent.




150 pounds

200 pounds

250 pounds

Average increase lean muscle
Average loss of body fat
Overall body composition improvement

13.2 lbs
21.6 lbs
34.8 lbs

17.6 lbs
28.8 lbs
46.4 lbs

22 lbs
36 lbs
58 lbs

Conclusion of the study’s authors:

“Diminished secretion of growth hormone is responsible in part for the decrease of lean body mass, the expansion of adipose-tissue mass (fat), and the thinning of the skin that occur in old age. The effects of six months of human growth hormone on lean body mass and adipose tissue reversed the equivalent of 10-20 years of aging.”

In another study published in New England Journal of Medicine, individuals received 6 months of growth hormone plus gonadal steroids, estrogen and progestin for women, and testosterone for men. Body composition was analyzed along with strength, lipid profile, and aerobic capacity. Conclusion:

  • Significant increase in lean muscle mass and a decrease in body fat by 3.5-18%
  • Significant increase in aerobic capacity
  • Improvement in the lipid profile (decrease in total and LDL “bad” cholesterol)
  • Decrease in blood pressure
  • Significant overall additive effect of estrogen, progesterone, testosterone and hGH resulting in dramatic improvements in body composition and functioning


USA Today, Edited Abstract of Article

High-profile Hollywood celebrities boast that using hormone modulation, including human growth hormone (hGH), has them looking better and feeling better. Praising hormone modulation as a way to stay healthy as long as one can, enthusiasm is growing for an anti-aging revolution, with hGH and vitamins as its focus.

HGH is produced by the body in the pituitary gland, and, as we age, the body’s natural hGH levels begin to drop around the age of 30. Advocates claim that supplementing the waning levels of our own hGH with injections of bio-engineered human growth hormone restores the body’s ability to grow muscle tissue, increases bone density, restores energy, enhances memory, and instills a sense of well-being. In other words, it brings one back to the level of age 30 or so.

Generally, a hormone replacement therapy program begins with a comprehensive evaluation of nutritional, metabolic, immune and hormonal functions. The preliminary diagnostics can reveal deficiencies in a number of areas—early signs of osteoporosis, thyroid conditions, blood-sugar imbalances, etc, and regimens are then prescribed to correct these deficiencies. Depending upon the patient’s particular medical needs, the program may include hGH.

Despite internet or advertising scams offering inexpensive sprays or pill forms of hGH, the hormone is potent only when injected. In combination with other anti-aging medical protocols, it has been shown to lower blood pressure, build lean muscle, decrease body fat, improve skin tone, heighten sexual potency, and ensure restful sleep. Some advocates have said that it also thickens hair and sharpens vision, but these are anecdotal accounts. Skeptics point out that the potential side-effects include joint discomfort, carpal tunnel syndrome, fluid retention, and insulin resistance. These problems, however, are generally from larger doses and corrected by simply adjusting the patient’s dosage. Other critics are concerned about “putting things into our body that aren’t naturally there.” Dr. Ronald Klatz, head of the American Academy of Anti-Aging Medicine (A4M), gets exasperated with such nay-sayers. “This is something that we have studied” and “has been in clinical use for the last 50 years. There are tens of thousands, if not hundreds of thousands, of people who have received growth hormone—whether they are children or adults.”

As 20 million baby-boomers turn 50 and another 22 million turn 40, more and more products and programs will be offered through anti-aging practitioners. It is important to remember that hGH is not effective unless it is injected. You need a doctor’s prescription and should be under the supervision of a qualified practitioner to monitor your hormone levels.


Large amounts of peer reviewed research, including long-term data, has demonstrated that growth hormone replacement has been shown to improve:

  • energy (1,2)
  • strength (1)
  • cardiac function (3,4,5)
  • blood pressure (6)
  • cholesterol levels (3,6,7,8)
  • insulin sensitivity (6,7,9)
  • cognitive function (10,11)
  • immunity (12,13)
  • psychological well-being (1,2)
  • decrease body fat (1,3,6,7,9,13,15)
  • increase lean muscle (1,6,14,15)
  • prevent and reverse heart disease (1,3,16,17)
  • prevent and improve osteoporosis (3,7,18)
  • increase quality of life (2,3,8)

There is an exponential decline in growth hormone release after age 21 with a 50% decline every 7 years. Almost all individuals over 40 years old have a growth hormone deficit and at age 60 growth hormone production is indistinguishable from those of hypopituitary patients with organic lesions in the pituitary gland. Life with low growth hormone is shown to be poor in quality and quantity (19).

While many endocrinologists feel the diagnosis of growth hormone deficiency requires the use of growth hormone stimulation testing, growth hormone and other stimulation tests are shown to be inaccurate, highly variable, non-physiologic, lack adequate sensitivity to detect relative growth hormone deficiencies, do not correlate with the presence of deficiency and do not predict who will respond to therapy (20-32). Requiring stimulation testing to confirm growth hormone deficiency is unnecessary, expensive and carries significant risk to the patient. Thus, they neither are appropriate to perform nor required for the diagnosis of growth hormone deficiency. A clinical diagnosis of growth hormone deficiency, often with support of low or low-normal IGF-1 levels, are the most appropriate means of making the diagnosis of relative growth hormone deficiency.

1. Gibney J, Wallace JD, Spinks T, Schnorr L, Ranicar A, et al. The effects of 10 years of recombinant human growth hormone (GH) in adult GH-deficient patients. J Clin Endocrinol Met 1999;84(8):2596-602.
2. Bennett RM, Clark SC, Walczyk J. A randomized, double-blind, placebo-controlled study of growth hormone in the treatment of fibromyalgia. Am J Med 1998;104(3):227-31.
3. Johannsson G, Svensson J, Bengtsson BA. Growth hormone and ageing Growth Hormone and IGF Research 2000;10(2):25-30.
4. Maison P, Philippe C. Cardiac Effects of Growth Hormone in Adults With Growth Hormone Deficiency: A Meta-Analysis. Circulation. 2003;108:2648.
5. Cho GY, Jeong IK, Kim SH, Kim MK, Park WJ, Oh DJ, Yoo HJ. Effect of growth hormone on cardiac contractility in patients with adult onset growth hormone deficiency. Am J of cardiology 2007;100(6):1035-9
6. Johannsson G et al. GH treatment of abdominally obese men reduces abdominal fat mass, improves glucose and lipoprotein metabolism and reduces diastolic BP. J Clin Endocinol Metab 1997;82:727-734.
7. Gotherstrom G et al. A prospective study of 5 years of GH replacement therapy in GH-deficient adults: sustained effects on body composition, bone mass, and metabolic indices. J Clin Endocrinol Metab 2001;86(10):4657-65.
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10. 7A. Aleman A et al. Insulin-Like Growth Factor-I and Cognitive Function in Healthy Older Men J Clin Endocrinol Metab 84:471–475, 1999.
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