HGH Growth Hormone
By Michael Lam, MD, MPH and Maria Sulindro, MD
Tremendous interest has emerged over recent years on the use of growth hormone to rejuvenate the body. The press is filled with stories of how Hollywood stars are using this drug as the latest “fountain of youth”. We seek to distinguish the facts from mere fiction.
Why Hormone Replacement?
One of the primary theories of aging is the neuroendocrine theory. This theory postulates that the signs of aging coincide with symptoms associated with the pausing of various organs. For example, pausing of the ovaries, found in all women, results in menopause and its many symptoms, include hot flashes. Similarly, the reduced level of testosterone secretion in men is responsible for the decrease of libido. Pausing of the pancreas leads to reduced insulin output and diabetes. Slowing of the thyroid gland can lead to hypothyroidism. Most major hormones decline with age after reaching a peak around mid twenties. These include DHEA, pregnenolone, melatonin, and growth hormone. The only hormone that increases with age is cortisol, also known as the “bad” hormone.
In particular, the growth hormone has generated worldwide interest. This is due to the amount of recent research, which shows that healthy aging adults can reverse the physical signs of aging by as many as 15 years.
What is Human Growth Hormone (HGH)?
Human Growth hormone (HGH) is a small protein molecule, which contains 191 amino acids in a single polypeptide chain. It is the most common hormone secreted by the anterior pituitary gland. Its rate of production peaks during adolescence when accelerated growth occurs. However, it generally remains in abundance in the pituitary gland ready to be secreted into the body. For some reason unknown, the amount of growth hormone secreted starts to slow after peaking. The measurable level of HGH in our body decreases 14 percent every ten years into old age. This reduced level of secretion occurs over a period of time, which leads to aging. Daily secretion from the pituitary gland diminishes with age to the extent that a 60-year-old man secretes only 25 percent of the HGH secreted by a 20 year old man.
HGH is actually released in pulses that take place during the day. Its release is especially prominent during the beginning phases of sleep. Secreted from the pituitary gland, these pulses are converted in the liver (within 20 minutes) to Insulin-like Growth Factor Type I (igf-1). Although igf-1 is not insulin, it acts like insulin as it promotes glucose transfer through cell membranes into the cell. More importantly, igf-1 elicits most of the effects associated with the growth hormone. It is measured in the blood and is the surrogate marker of growth hormone in the body.
Use of HGH in Anti-Aging Medicine
Dr. Harvey Cushing first discovered the Growth Hormone in 1912. It was first isolated from human and monkey cadavers through glandular extraction in 1956. Two years later it was used to treat dwarfism in children by injection. Dr. Daniel Rudman conducted a landmark double blind study in 1989. The results of this study showed conclusively that age reversal was possible with the use of GH. This study included adult men who had measured deficiencies in growth hormone and were aged between 61 and 73 years. They were injected with GH produced from recombinant DNA synthesis. In 1990, Dr. Rudman’s results were reported in the prestigious New England Journal of Medicine.
Results of the double blind study showed:
– Lean Body Mass +8.8%
– Bone Density +1.6%
– Adipose Tissue (Fat) Mass -14.4%
– Skin Thickness from 4 sites +7.1%
In short, skin became thicker, muscle mass increased, age-related stomach fat disappeared and lost bone from the spine was restored.
The effects of six months of human growth hormone on lean body mass and adipose-tissue mass were equivalent to 10 to 20 years of reversed aging. Here, the most significant result relating to anti-aging exists between the ratio of muscle to fat.
A quote from Robert Klatz’s book Stopping the Clock aptly summarizes the full report made by this relationship and the implications: “…it helps to recall the way our muscle-fat ratio tends to change as we age. Some 80 percent of a young adult’s body are lean body mass: (which is) muscles, organs, and bone. Only 20 percent is fatty (adipose) tissue. For most people, after age 30, muscles atrophy, partly from genetic programming, partly from underuse. Every decade thereafter an average of 5 percent of lean body mass is replaced by fatty tissue, so that by the time most of us reach age 70, we’ve gone from an 80-20 lean-fat ratio to a ratio that is closer to 50-50.”
The increase in fatty tissue is related to a variety of cardiovascular problems, while the loss of lean body mass is linked to the elderly losing energy, strength, and mobility. Any cause that can slow or reverse the trend towards more fatty tissue in effect slows or reverses the aging process itself.
Although drugs and therapies that claim to reverse aging are nothing new, only Dr. Rudman’s study passes the gold standard of drug testing: controlled, randomized, double-blind clinical study with reproducible results.
Other Studies on Growth Hormone
Since Dr. Rudman’s landmark study in the field of HGH, 100 reputable studies have been performed which documented the safety and legitimacy of this outstanding therapeutic approach.
After Dr. Rudman’s death, a study was conducted at the same institution at which Dr. Rudman completed his original work. The following information was taken from this study at the Medical College of Wisconsin between 1994 and 1996:
Recipients of HGH were given low dose/high frequency dosages. The information was compiled from 308 randomly selected self-assessment questionnaires that were completed by 202 patients.
– 88% reported improvement in Muscle Strength
– 81% reported improvement in Muscle Size
– 71% reported improvement in Body Fat Loss
– 81% reported improvement in Exercise Tolerance
– 83% reported improvement in Exercise Endurance
– 71% reported improvement in Skin Texture
– 68% reported improvement in Skin Thickness
– 71% reported improvement in Skin Elasticity
– 51% reported improvement in Wrinkle Disappearance
– 38% reported improvement in New Hair Growth
– 55% reported improvement in Healing of Old Injury
– 53% reported improvement in Back Flexibility
– 53% reported improvement in Sexual Potency/Frequency
– 73% reported improvement to Common Illness
– 62% reported improvement in Duration of Penile Erection
– 57% reported improvement in Frequency of Nighttime Urination
– 57% reported improvement in Hot Flashes
– 84% reported improvement in Energy Level
– 62% reported improvement in Memory
Such findings, which became a stir in the medical industry create a huge demand for human growth hormone.
Effects of HGH Enhancement
Effects of HGH enhancements include the loss of fat and wrinkles as well as the growth of hair and gains in muscle. Improvements in sex drive, brain function, vision, immune function, and cholesterol profile have been widely determined as well.
Signs of Declining Hormonal Health
The following are 15 common signs of declining hormonal health:
Do you go through mood swings easily?
Do you anger easily?
Do you have trouble falling or staying asleep?
Is your sex life declining?
Do you have problem concentrating?
Do you often get cold or feel sick?
Is your total blood cholesterol over 240?
Is your HDL cholesterol under 50?
Do you have high blood pressure?
Does the skin on your face and neck appear to hang?
Is it getting harder to exercise?
Is your grip strength weakening?
Is your endurance level less?
Is your breathing more labored when you exercise hard?
Are you age 45 and above?
If you answer “yes” to many of the questions, you should consult an anti-aging physician for further evaluation as hormonal replacement may be warranted. If you answer negatively to most of the questions above, chances are your hormonal health is within normal limits and no intervention is necessary.
Symptoms of HGH Deficiency in Adults
There are numerous symptoms to indicate a HGH deficiency. These symptoms can be broken down into at least four different categories.
Symptoms in anabolic tone include: reduced lean body mass, reduced skeletal muscle strength, reduced exercise performance, increased body fat, and increased abdominal fat.
Symptoms in lipid effects: increased LDL cholesterol and decreased HDL cholesterol; in bone defects: osteopenia (lack of bone).
Symptoms in protein synthesis: thin skin, lack of collagen, decreased size of organs, decreased nail, and hair growth.
Symptoms in mental health: reduced energy, emotional instability, poor memory and concentration, depression, and reduced sex drive.
Growth Hormone Enhancement and Replacement
Growth hormone enhancement and replacement can generally be divided into the following categories:
A. HGH Injections
B. Amino Acid Secretagogue
C. Homeopathic Oral Spray
D. Homeopathic Tablets
E. Homeopathic Skin Cream
F. Oral Short Chain Peptide Secretagogue
G. GHRF (Growth Hormone Releasing Factors)
I. HGH Syngergizing Factors
A. Human Growth Hormone Injections
For years after Dr. Rudman’s study, the therapeutic approach to dominating the growth hormone field was through the injection of the human growth hormone. Injectable HGH is currently produced by recombinant DNA biotechnology methods. Only a few pharmaceutical companies worldwide are capable of producing injectable HGH.
However there were many problems associated with using this method. Fortunately, these setbacks were not safety related. For example, the injections could cost up to $1,000 per month. Since the objective of this procedure was to mimic the body’s secretion pattern of HGH throughout the day, the doses tended to be low, although they were delivered in higher frequencies. As a result, many people complained about the daily injections. No major side effects were reported with the exception of some minor joint aches and pains and fluid retention. These minor complications, however, tended to disappear within the first two months.
Fortunately there were no reported cases of cancer or serious degenerative illnesses. However there would be a decrease in energy level when a patient tops the HGH injections. It was found that the body composition would essentially remain unchanged if accompanied by an exercise and diet program. Although injections of Human Growth Hormone may not be the program of choice for many people, statistics demonstrate overwhelmingly its impressive effectiveness.
However, interest in HGH injections never reached critical mass. Perhaps the cause for this is the injection method, which is considered troublesome.
B. Amino Acid Secretagogues
A secretagogue (pronounced se-cre’-ta-gog) is a natural polyamino acid chain that is postulated to initiate the pituitary gland to release growth hormone. It is the precursor to HGH. While HGH causes the body to act as if the pituitary has released growth hormone, a secretagogue actually causes the release of it. Hence a secretagogue causes the bodies own natural processes to produce growth hormones. Secretagogues do not act as growth hormones at all as they stimulate the pituitary gland to secrete growth hormone.
Interestingly, the inconvenience of HGH injections first led to the discovery of Secretagogues. For years, it was believed that the pituitary gland, which produces growth hormones, dries up as a natural effect of aging. Science has recently discovered that growth hormone resides in the pituitary gland, which stops the release due to aging. Scientists then discovered that certain combinations of amino acids could actually spur the pituitary gland to release the growth hormones. Experiments soon led to the right combinations.
Two different opinions however emerged in the approach of producing the most effective secretagogue. Some believed that secretagogues should be derived from natural substances and others believed that synthetic substances are just as effective. Synthetic secretagogues are currently unavailable for use since they are still undergoing clinical trials.
Since natural secretagogue is the most practical approach, there are no side effects. In comparison with HGH, their potency and efficacy are low. Since these are orally taken, they can be a first line approach for those who may not choose HGH injections.
This category of HGH products uses amino acids as “secretagogues,” which stimulate the pituitary gland to produce HGH. Other proprietary agents are usually part of the powder/tablet mix, which provide each product with a presumed marketing advantage. Studies show that certain amino acid combinations such as L-lysine and L-arginine, L-ornithine and L-glutamine can stimulate pituitary HGH. While this is theoretically plausible and positive clinical results have been widely reported, published double blind controlled studies show evidence that these other proprietary factors provide additional pituitary HGH secretion is still incomplete at best.
Most studies reveal at least two grams of amino acids are needed to have any effect on pituitary HGH stimulation.
Glutamine is the most abundant amino acid in the body and causes GH secretion. It is a conditional amino acid as the body may not be able to synthesize it under stressful conditions. Traditionally it has been used to strengthen the immune system. The standard anti-aging intake is 50 mg to 1 gm twice daily.
Glutamine is a neurotransmitter in the brain. It is essential for proper brain functions, immune functions, kidneys, pancreas, bladder, and liver functions.
Glutamine becomes one of our body’s most powerful antioxidants in high quantities. Many people, especially those in weight training, add this amino acid due to its benefit in muscle metabolism. Supplementation of two to three gm/day is quite common. For those who plan to take extra doses, it is best to divide the doses throughout the day with up to four servings daily.
Two grams of glutamine was shown to cause a four fold increase in Growth Hormone levels.
Lysine is an essential amino acid, which affects bone formation, height, and genital function. It also boosts the effects of arginine. The recommended dosage is one gram on an empty stomach one hour before bedtime and before exercise.
Ornithine is a non-essential amino acid. It is used to potentate the effect of Arginine. The suggested dosage is one gram at bedtime. Doses of more than two to five grams have been known to cause diarrhea.
C. Oral Peptide Secretagogues
HGH is a hormone made up of a long chain of amino acids. Only a portion of the long chain of amino acids makes up the active ingredient. Researchers have been able to identify and extract these active peptides, which are usually five to ten amino acids linked together in a chain. These are then stabilized and formulated into a power or tablet effervescent form. The oral tablets are dissolved in water to be taken before bedtime on an empty stomach. This is to stimulate the release of HGH from the anterior pituitary, which peaks during the early phase of sleep. The effervescent form is best to draw the peptide away from the gastric juice closer to the mucous for better absorption. Gastric juices are highly acidic. Peptides are proteins that are easily denatured when exposed to an acidic environment. Extraction of the peptide is a tedious process. Peptides are not stable enough to maintain its activity in an aqueous environment. Thus, the peptide is formulated in the oral tablet format. Secretagogues using peptides are abundant in the marketplace. They are sold as a natural nutritional supplement and no FDA approval is required. However some unscrupulous operators simply use ground bovine pituitary gland and pass them off as secretagogues. The consumer is often faced with the arduous task of identifying which is the real secretagogue.
An effective secretagogue could easily raise igf-1 levels, although the result is not as significant as growth hormone injections. Clinically many users have reported better sleep, increased alertness during the day, and less joint pain.
igf-1 levels may not be the best indicator of how effective a secretagogue for the GH receptor sites may be damaged. A low igf-1 level does not mean that the body’s growth hormone level has not increased. It simply means that that the level is not accurately measured.
D. Homeopathic Oral Sprays
The motive behind HGH oral sprays is to deliver the large HGH protein via the oral mucous into the systemic circulation instead of risking it being degraded by the stomach and liver metabolism if taken orally. Unlike amino acid secretagogues, HGH oral sprays contain HGH itself. All HGH oral sprays are deemed homeopathic because this is the only way to sell oral HGH legally. There is considerable controversy as to whether the large 191 amino acid HGH protein can be effectively delivered through the oral mucous and produce systemic effects similar to HGH injections.
The theoretical problem associated with homeopathic oral sprays is that the growth hormone with its large molecule size cannot penetrate intact into the membranes to any significant degree. Hence the hormones would not be useful in a nasal spray or oral form. Some companies have developed special “carriers” but the effectiveness remains in doubt.
Oral sprays may contain recombinant human growth hormone (rhGH) but it is not certain which manufacturers use this purer form. Some have used the bovine form along with various peptides, growth factors, amino acids, animal extracts, minerals, ethanol, and glycerin. The main ingredient, by volume, is water. The pharmaceutical-grade rhGH is diluted to a desired (and legal) homeopathic concentration. Some products claim to be “hand-succussed” and made according to the Homeopathic Pharmacopoeia of the United States (HPUS). Hand-succussed is not related to absorption but to the traditional way of making homeopathics and transferring the “energetic” quality.
Another issue raised by some doctors is whether this HGH protein can be stabilized in an aqueous (water) solution without degradation over time. The HGH molecule loses potency very rapidly when dissolved in solution. The effective shelf life is not known. Genentech’s iHGH product called Nutropin AQ, a sterile liquid, is intended for subcutaneous administration. It has an HGH concentration of five mg/mL and is preserved only by sodium chloride (8.7 mg/mL), phenol (2.5 mg/mL), polysorbate 20 (two mg/mL) and sodium citrate (5 mM). This liquid HGH has a shelf life of 18 months from the date of manufacture.
Ethanol is often used in these oral sprays to prevent bacterial growth, but the effect this alcohol has on the HGH protein structure may render it inactive. This is especially true with high concentrations of alcohol. Several products contain as high as 47 per cent of alcohol.
E. Homeopathic Oral Tablets
The three studies used two different homeopathic HGH formulations (6X+12C and 6C+100C+200C) and were conducted in three separate areas of the United States. In Seattle, the study lasted 30 days and involved 15 subjects. In Santa Fe, New Mexico, 46 subjects were part of a 21-day homeopathic study. In Boulder, Colorado, 101 subjects were involved in a crossover 42-day study period. The studies reported significant increases in energy, weight loss, and upper arm size; decreased hip size; and relieved joint and knee swelling, compared with placebo. The authors concluded with three major findings. First, homeopathic HGH produced a physiological effect as shown by reproducible increases in serum igf-1 levels compared with placebo. Secondly, multiple beneficial effects of treatment were demonstrated. These included increased lean mass, weight and fat loss, relieved fatigue and improved psychological well being. Lastly, subjects who received homeopathic HGH reported relief from symptoms such as fatigue and poor skin appearance when they first entered the studies.
With respect to homeopathic HGH increasing serum igf-1 levels, the Santa Fe trial showed an 18 percent increase in serum igf-1 after only seven days. Subjects in the Seattle group reported an 18 percent increase and the Boulder group 21 percent increase within 21 days of starting HGH. Would levels continue to increase, return to baseline, or drop below baseline in the long-term period? Longer duration studies with more subjects are required to fully assess the effects homeopathic oral homeopathic HGH has on igf-1 levels.
There are other reservations on the test findings. Primarily, the placebo effect in these studies was stronger than the normally observed 30 to 40 percent. In each placebo group, there was a transient 12 percent increase in serum igf-1, and placebo effects were as high as 100 percent in the self-perceived quality-of-life topics. Some of the major placebo effects were increased energy, enhanced physical endurance, relief from carpal tunnel syndrome, reduced appetite, change in hair color, increased skin thickness, fewer skin wrinkles, and relief from skin rashes. However, the studies demonstrated treatment trend effects beyond those of placebo in terms of serum igf-1 levels, increased lean body mass, increased physical strength, decreased hip size, improved sleep quality and decreased blood pressure.
F. HGH Skin Creams
Is it possible for a skin cream to provide benefits that would mimic what non-injectable HGH products claimed? Although some suppliers claim that it is possible, the large molecular size of a growth hormone makes absorption by skin highly unlikely.
G . HGH BOOSTING AUXILLARY HORMONE REPLACEMENT
Certain hormones have a synergistic effect in boosting the body’s secretion of GH. Besides growth hormones, other hormones decline with age as well. It is thus necessary to replace them to ensure one’s youth and health. Secondly, different hormones have different effects on our body. Thirdly, raising the levels of other hormones will decrease the amount of HGH needed. Some of these hormones are estrogen, progesterone, testosterone, DHEA, and Melatonin.
Progesterone functions in many capacities. It is often taken to counter the effects of estrogen, which is normally used by postmenopausal women. It depends on the prescription. Natural progesterone is available as well and is known to have far fewer side effects. Progesterone has many functions. First, it is both a precursor to other adrenal hormones and a GH stimulant. It also promotes lipolysis (breakdown of fat) and protects against endometrial cancer. Progesterone is also known to eliminate the risk of endometrial cancer when given with estrogen for 10 or more days per cycle. Lastly, progesterone helps to normalize the levels of blood sugar, zinc and copper.
Testosterone is a male sex hormone and the most potent stimulant of GH. It decreases with age, starting in mid 40′s. Only 40 percent of men’s youthful level of testosterone still exists at the age of 80. Studies have shown that this loss accounts for the “pot belly” and loss of muscle mass in middle aged men. Testosterone replacement therapy (TRT) is as powerful an anti-aging effect as estrogen or progesterone replacement in women. Many benefits are associated with taking testosterone such as renewed strength, improved balance, raised blood cell count, increased libido and lowered LDL and cholesterol. It also reduces the loss of bone mass in men. However, TRT has its side effects, which include higher levels of PSA (prostrate specific Antigen) and a rise in hematocrit. It is advisable to take the PSA test every six months and an ultrasound every three years to check for any abnormalities when using TRT. Total hormone replacement, which includes melatonin and DHEA, may actually have immune rejuvenating and cancer surveillance properties that protect against prostate cancer. Testosterone can be given as an intra-muscular injection, suppositories, a patch to the scrotum, oral micronized capsules or sublingual lozenges.
Estrogen represents an entire family of female related hormones. It helps to reduce heart diseases and controls LDL cholesterol. It is often used to prevent hot flashes and mood swings associated with menopause. Other benefits include the prevention of heart disease, control of the rapid decline of bone density after menopause, improvement of body composition, protection against Alzheimer’s disease, and stimulation of GH.
DHEA is the most abundant of all steroids and is released from the adrenal glands. Cholesterol actually produces DHEA when the pituitary releases ACTH. DHEA is involved in the production of testosterone, estrogen, progesterone and coritcosteroids. The decline of DHEA parallels that of growth hormone. By the age of 65, the body produces only 10 to 20 percent of the DHEA that was first created at the age of 20. It has been shown in animal studies to act as an agent of anti-obesity, anti-cancer, anti-autoimmune disease, anti-stress and anti-infectious disease. In other words, DHEA is a total anti-aging supplement. It may also boost brain function as the brain tissue contains more than six times DHEA than any other tissue in the body. Increasing igf-1 levels may cause anti-aging effects. Furthermore, DHEA is an inexpensive alternative to GH. Doses range between 25 to 50 mg per day. DHEA levels should be measured intermittently and a resting cycle should periodically be observed.
Melatonin is a hormone with powerful antioxidant properties. It reportedly has a host of benefits as it boosts the immune system, prevents cancer, improves heart functions, lifts the mood and enhances sleeping patterns. Secreted by the pineal gland, melatonin is the timekeeper of the brain and controls the circadian rhythms. Doses vary from person to person. Low dosages of 0.3 mg to 1 mg can reduce the sleeping time as well as increase the quality of sleep. Some people require as much as 60 mg before feeling its effects. The recommended starting dosage is 0.5 mg to 1 mg before bedtime. An increase of up to 5-10 mg per day is recommended if needed. This is contraindicated in pregnant or nursing woman, children, women trying to conceive, people who are on prescription steroids, those who have mental illness, or people with severe allergies or immune system cancers such as lymphoma.
H. igf-1 REPLACEMENT
Science is attempting to manipulate igf-1 levels, which would then produce the responses needed to affect age reversal. Currently, there are no significant studies conducted on igf-1. It will be years before clinical trials are completed. Another problem posed is how the FDA will classify igf-1 since it is neither a pharmaceutical formula nor a supplement.
With such questions yet to be resolved, one may wonder where the science of growth hormone is headed. It looks as if science will soon discover a small, inexpensive, safe pill that a person could take every day to raise HGH levels – a kind of anti-aging aspirin. This would be the ultimate secretagogue. Extensive clinical trials are already underway.
I. HGH syngergising factors
Lastly, many factors affect the ability of the body to release HGH and form igf-1. These factors include physical and emotional stress, chronic liver dysfunction, poor diet, and genetic predisposition. Other factors leading to the decrease of HGH release are obesity, zinc and magnesium deficiency, and an increase in blood sugar and/or insulin levels. On the other hand, factors increasing HGH include calorie restriction, high testosterone or estrogen levels, high doses of amino acids (L-Arginine, Glutamine, Lysine), increase in calcium, and continuous intensive exercise.
Regardless of which mechanism is chosen to increase endogenous growth hormone level, a high potency vitamin and mineral supplementation program, coupled with a precise anti-aging exercise program, healthy anti-aging diet, and the right attitude are vital because they work synergistically with HGH to promote HGH secretion. In addition, HGH can be enhanced with supplements such as Chromium Polynicotinate, which helps lower circulating insulin and blood sugar.
With regards to HGH Diet enhancement, it is recommended that 50 to 60 percent of food intake should consist of the carbohydrates found in fruits and vegetables. Complex carbohydrates such as fruits and vegetables, as compared to rice and potato, are highly recommended. As complex carbohydrates break down slowly, the abrupt rise of insulin in the blood that occur with simple starches is therefore restricted. Protein should account for 20 to 30 percent and fat 10 to 20 percent of the remainder of food consumption. These percentages of food intake represent the necessary amounts to allow HGH to be released. Most importantly, the amount of sugar intake should be limited as sugar increases the amount of cortisol hormone in the body, which speeds up aging.
What Should You Do?
Not everyone needs growth hormone replacement. Those who wish to be on the program can choose from natural peptide secretatgogues to injectable growth hormone. The decision on which method to use depends on individual preference, medical history, and budget.
While growth hormone injections are the most expensive, they are often recommended for those in their 60s and 70s who do not wish to wait. For those in their 40s and 50s, the natural secretagogue with prohormone amino acids is a reasonable treatment for a few months. If clinical improvements are seen, there may not be a need for the injectable HGH.
It is important to note that injectable HGH must be carried out under the care of a physician. The normal protocol calls for daily injections for a few months with resting periods between cycles. During these resting periods, which are usually a month for every three months of injection, it is often advisable to use the oral secretagogue supplementation to maintain a stable level of igf-1.
For those who wish to enhance their hormonal health but do not want to use secretagogues, taking amino acids is a simple and natural way. Supplementation with other hormones such as DHEA and pregnenolone are also effective, although it is generally less effective than the use of peptide secretagogues.
For those who do not wish to take any hormone replacements or supplementations, an intensive strength training which involves the large muscles such as the back, thigh, and chest, coupled with an intensive cardiovascular exercise program have been shown to increase the growth hormone level in the body. Athletes who train heavily are known to maintain youthful levels of HGH right into their 70s. It is not a coincidence that all major studies of exercise show that the results when compared to HGH therapy are similar. These results include an increase in bone density and muscle mass, reduction of cholesterol, blood pressure and triglycerides, a decrease in body fat, and an increased life expectancy. Exercise and diet both promote the control of insulin. Not surprisingly, HGH dosage is decreased with vigorous exercise.