Human Growth Hormone HGH

Human Growth Hormone HGH

You may have heard about human growth hormones (HGH) and how HGH is a great anti-aging supplement on TV or in promotional fliers you got in the mail.  After studying the potential of HGH in the health of baby boomers, I started taking a supplement called GenF20Plus.

In this article I offer what I learned before I started taking this supplement.  I’ll provide some background on growth hormone deficiency, the idea of growth hormone therapy and human growth hormone supplements and why these therapies show so much promise for people over 40.  I’ll also discuss some of the research on the topic (including effects and side effects) and details about the specific ingredients used in GenF20Plus.

Some of this discussion gets into the details of what items science has found that actually affect HGH production.  This is critical to know because oral growth hormone supplements incorporate a wide variety of ingredients and you want to find ingredients that may actually be useful when selecting a supplement.  I have included a list of references at the bottom with footnotes in brackets along the way, so you know that the information summarized here came from valid scientific sources.


Human Growth Hormones

 A hormone (from Greek ὁρμή, “impetus”) is any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.

Hormones, in general, are defined in the box to the right.  Natural human growth hormone (somatotropin,  rather than somatropin that is produced by recombinant DNA technology),  is produced by the pituitary gland which is regulated by the hypothalamus.  What the hypothalamus tells the pituitary to do, with regard to releasing HGH, depends upon exercise, nutrition, and sleep (that tend to increase release) and free fatty acids (that tend to decrease release).  Age, sex, diet, exercise, stress, and other hormones also affect HGH release.

Human growth hormone, upon release from the pituitary, enhances muscle growth, among other things.  Some is converted by the liver into insulin-like growth factor (IGF-1) that enhances bone growth.

While the release of HGH varies greatly from person to person, it commonly peaks about an hour after going to sleep.  Further,  there are typically peaks every three to five hours with blood levels of HGH being quite low between these peaks.   The effect of age is of most interest to us here because research has shown that young adolescents secrete 700 μg/day, while healthy adults secrete HGH at the rate of about 400 μg/day [1].  Actually, HGH levels decline with age more like the chart shown above.  This suggests that adults may have a growth hormone deficiency, at least in comparison to kids.


What does HGH Do?

Effects of HGHMost obviously, HGH stimulates growth during childhood, but, for older folks, it tends to strengthen the human body.  More specifically:

  • Increases calcium retention, and strengthens and increases the mineralization of bone
  • Increases muscle mass
  • Promotes the breakdown of fats in the body
  • Increases protein synthesis from amino acids
  • Stimulates the growth of all internal organs except the brain
  • Plays a role in keeping internal processes stable
  • Reduces liver uptake of glucose
  • Promotes production of glucose from fatty acids in the liver to prevent low blood sugar
  • Contributes to the maintenance and function of pancreatic islets that produce hormones
  • Stimulates the immune system
  • Increases thyroid hormones in the cells

These are all good things for the human body, so the notion that increasing HGH levels would facilitate improvements in all these processes is quite attractive.

Excess HGH

Too much HGH can, however, create issues.  Pituitary tumors, usually not seen until over the age of 50, can generate a lot of  HGH causing the following issues associated with excess HGH:

  • thickened bones of the jaw, fingers and toes
  • sweating,
  • pressure on nerves (as in carpal tunnel syndrome),
  • muscle weakness,
  • excess sex hormone-binding globulin that reduces the activity of sex hormones,
  • insulin resistance
  • reduced sexual function.

Clearly excess HGH will not make an adult taller and is to be avoided.

HGH Deficiency

Human growth hormone deficiency in adults, relative to average levels of HGH seen in the adult population, is rare, but may cause:

  • reduced lean body mass,
  • poor bone density,
  • poor memory,
  • social withdrawal,
  • depression,
  • loss of strength, stamina, and musculature.

Thus human growth hormone deficiency is also a bad thing.  Many of these symptoms are seen as we age.  This suggests that increases in HGH could be beneficial for older people even though existing levels are in the ‘normal’ or typical range for older people.

Can Increasing HGH Really Help?


The New England Journal of Medicine published a study in 1990 that showed statistically significant increases in lean body mass and bone mineral density in 12 men over age 60.[14]  While the authors did not claim that HGH had reversed the aging process itself, some people decided that this made HGH an effective anti-aging agent and began promoting it for that use.

A 2007 analysis of clinical studies by the Stanford University School of Medicine showed that HGH given to healthy elderly people increased muscle by 2 kg while decreasing body fat by the same amount.[15]  No other factor that might suggest increased fitness was found.  Further, there was no gain in muscle strength, suggesting that perhaps the effect was related to additional water storage in the muscles.

Studies using somatropin, produced by recombinant DNA technology, and injected into the bloodstream show varying results. When they are all analyzed in combination, the positive effects of supplemental HGH seem to be minimal.  That, however, does not prevent doctors from prescribing HGH for uses that are not in accordance with the product label.

There are also side effects. These side effects of injecting HGH into the blood stream are essentially what is seen with excess HGH plus a couple of other things:

  • joint swelling,
  • joint pain,
  • carpal tunnel syndrome,
  • increased risk of diabetes.[15]
  • an immune response against HGH.

Recombinant HGH may also be associated  with Hodgkin’s lymphoma.[16]

Taking oral growth hormone is totally ineffective because it is digested in the stomach before it can reach the bloodstream.  That leaves us with natural human growth hormone that is produced in the human body (somatotropin).


Taking HGH from one person and injecting it into another is not a practical solution, although it has been tried with very limited supplies.  Those limited supplies led to the creation of recombinant HGH and many studies of its effects.

Studies on the effects of natural HGH produced within an individual seem to be pretty much limited to the effects of high or low levels of HGH as discussed above and the effects of various compounds on the release of HGH to the body.  Supplement manufacturers are trying to develop products that stimulate production and release of an individual’s own HGH.


How Various Things Affect HGH Release

The supplement industry has taken the approach of trying to increase natural production of HGH by incorporating various ingredients in their products.  Research has shown that certain ingredients do affect HGH release to some degree.  Increase in natural human growth hormone has not been shown to have adverse effects until HGH levels get too high — something that is difficult to achieve without direct injections of HGH, in the absence of disease.


  • sex hormones[2] , particularly increased androgen secretion during puberty (in males and females) and estrogen
  • clonidine and L-DOPA  stimulate the release of the molecules from the hypothalamus that tell the pituitary to release more HGH [3]
  • α4β2 nicotinic agonists, including nicotine, acting with clonidine [4,5,6].
  • hypoglycemia (low blood sugar), arginine [7] and propranolol by preventing the hypthalamus from telling the pituitary to decrease HGH release [3]
  • deep sleep [8]
  • niacin as nicotinic acid (Vitamin B3) [9]
  • fasting [10]
  • vigorous exercise [11]
  • ghrelin [17], the hunger hormone named from growth hormone release-inducing


  • high blood levels of HGH and IGF-1 tell both the pituitary and the hypothalamus to back off on releasing HGH [12]
  • hyperglycemia (high blood sugar) [3]
  • glucocorticoids, steroid hormones that regulate sugar metabolism [13]
  • dihydrotestosterone, an androgen hormone that affects development of secondary sex characteristics

 Formulating HGH supplements (Secretagogues)

GenF20Plus Label - Click for a larger version

GenF20Plus Label – Click for a larger version

Formulations that aim to increase natural secretion of HGH into the bloodstream are sometimes called secretagogues.  Companies that produce the best human growth hormone supplements use science to identify ingredients that have the desired effect then incorporate appropriate amounts of those ingredients into their supplements.  Often weak science is used simply because the ingredient might work and won’t have adverse effects in any case.

As I mentioned above, I recently started taking an HGH supplement called GenF20Plus to see if I could detect any changes in my body.  I chose this particular product because I found the results of a clinical trial that suggested it had some positive effects.  It also contains many ingredients that have been shown to be associated with HGH release.   The following ingredients are provided in four enteric coated tablets that are to be taken at the rate of two tablets, twice a day on an empty stomach:

GTF Chromium (as chromium yeast) 400 mcg (333% of DV): Chromium yeast, is simply yeast fortified with chromium. GTF stands for Glucose Tolerance Factor. “Chromium is an essential nutrient required for sugar and fat metabolism.  The estimated safe and adequate daily dietary intake for chromium is 50 to 200 mcg. However, most diets contain less than 60% of the minimum suggested intake of 50 mcg.  Insufficient dietary intake of chromium leads to signs and symptoms that are similar to those observed for diabetes and cardiovascular diseases. Supplemental chromium given to people with impaired glucose tolerance or diabetes leads to improved blood glucose, insulin, and lipid variables. Chromium has also been shown to improve lean body mass in humans and swine. Chromium is a nutrient; therefore, it will only be of benefit to those who are marginally or overtly chromium deficient. Trivalent chromium has a very large safety range and there have been no documented signs of chromium toxicity in any of the nutritional studies at levels up to 1 mg per day.” [18]  While I was unable to find studies showing an increase in HGH levels in humans, a study of pigs found that chromium did increase growth hormone levels. [19]  Other studies [20] show a tendency to lower blood sugar levels, something that has been shown to be associated HGH release.

L-Arginine HCL (520 mg) “studies have shown that resting growth hormone responses increase with oral ingestion of L-arginine and the dose range is 5-9 gm of arginine. Within this range there is a dose-dependent increase and higher doses are not well tolerated. Most studies using oral arginine have shown that arginine alone increases the resting growth hormone levels at least 100%, while exercise can increase growth hormone levels by 300-500%. The combination of oral arginine plus exercise attenuates the growth hormone response, however, and only increases growth hormone levels by around 200% compared to resting levels.” [21]  This 520 mg dose of L-Arginine is quite low compared to the effective dosage associated with increased HGH levels and may be insufficient to have any effect.  However,  it becomes much more potent in combination with L-Lysine (see below).

L-Glutamine (460 mg) As already noted, L-Glutamine will increase HGH release.[7] As with L-Arginine, exercise can produce comparatively overwhelming amounts of HGH.  This dosage is fairly low compared to experiments using 2 grams.

L-Glycine (460 mg) “Glycine is one of the stimulatory agents inducing the pituitary gland to secrete HGH.” [22]  This dosage is higher than that used in the noted study.

L-Tyrosine (400 mg) L-DOPA is produced from the amino acid L-tyrosine in the body by the enzyme tyrosine hydroxylase. L-DOPA has been shown to increase the release of HGH. [3]

L-Lysine (400 mg)  L-Lysine by itself does not affect HGH levels. However, arginine and lysine in combination increase HGH production considerably.  One study showed that a combination of 1200 mg of arginine combined with L-lysine significantly raised HGH from two to eight times the baseline value at 30 to 120 minutes after consuming the amino acids.[23]

Tribulus terrestris (vine) (320 mg)  Tribulus terrestris, is used in traditional, ancient medicine in Greece, China and India (Ayurvedic medicine) for a variety of purposes. It is often touted as a  way to increase testosterone levels, however various studies show it has no effect in that arena.[24,25,26,27].  I could find no research that suggests it could increase HGH levels.

Astragalus (root)  (240 mg) Astragalus is a potent anti-oxidant, however there is limited research on its effects upon HGH production.  One study found that it did release HGH in rat pituitary cells.[28]

Colostrum (10%)  (200 mg)  Insulin-like Growth Factor (IGF-1)  favors muscle growth and the burning of fat over glucose. [29]  It is normally produced from HGH in the liver. One study found that long-term colostrum supplementation with 20 grams per day increases IGF-1 levels.[30]  Another study found that “daily supplementation with 60 gm of bovine colostrum for 4 weeks does not change blood IGF-1 or IGF binding protein-3 levels and does not elicit positive results on drug tests.”[37]  Still another study showed that supplementation with bovine colostrum does not improve performance, in elite female rowers.[36]  Whether colostrum has the desired effect or not,  the 200 mg dosage is far below the dosages used in the various studies and is not likely to have any effect regardless. As noted above, high levels of IGF-1 can cause the pituitary to release less HGH.

Note that IGF-1 is a banned substance included on the World Anti-Doping Agency (WADA) prohibited list, so taking it directly is a bad idea, especially for those involved in competitive sports.  Natural products that enhance it’s production in the body would not normally run afoul of this restriction.

Deer Velvet Antler (200 mg)  Deer antlers are bone structures.  In temperate zones, deer antlers are shed and regrown each year.  While they grow, they are covered with a protective skin called “velvet” that supplies nutrients and oxygen to the bone. [31]  During growth the antler is basically a cartilage that eventually is calcified and hardens.  Before it hardens, the antlers are harvested as “deer velvet antler.”  This is big business among deer farmers in New Zealand.

One study showed that supplementation with this ingredient had no effect on human growth hormone. [32]  Another study analyzed supplements with this ingredient and found the presence of a pharmaceutical protein, human (not deer) IGF-1,  in four of six commercially available products sold as all natural, nutritional supplements.[33]  Note, as above, that IGF-1 is a banned substance included on the World Anti-Doping Agency (WADA) prohibited list.  GenF20Plus was not among the products tested.

Assuming that deer velvet antler has not been adulterated with human IGF-1, does it have any effect upon human growth hormone levels?  The first study [32] suggests, no.  New Zealand researchers looked at seven randomized controlled studies of the effects of deer velvet antler and found: “Claims made for velvet antler supplements do not appear to be based upon rigorous research from human trials, although for osteoarthritis the findings may have some promise.” [34]  I can only conclude that this ingredient has no effect on HGH, or probably anything else except maybe osteoarthritis.

GABA (gamma amniobutyric acid)  (200 mg) GABA has been shown to increase release of HGH when ingested at an oral dose of 5 grams per day. [35]

L-Isoleucine  (160 mg)  Isoleucine is an amino acid that must be ingested since the body cannot manufacture it on its own.  I found one study that showed low levels of some amino acids, including isoleucine, in patients with HGH deficiency.[38]

L-Valine (160 mg)  The study mentioned above [38] found that lean body mass in patients with HGH deficiency showed improvement that correlated with increases in the total of isoleucine, leucine and valine over baseline levels.  Apparently supplementing with valine alone has little effect.  Valine, however works along with similar amino acids, leucine and isoleucine.

Pituitary powder (anterior) (120 mg) There is not much research on this ingredient.  I found one 1964 study [39] that used it as a source of vasopressin.   Researchers fed it to old rats to see if it would prolong life.  They found that after 180 days, 8 of the original 18 controls (44%) were still alive while 22 of 36 treated rats (61%) were still alive. The treated rats were also in generally better physical condition. Another study [40] found: “Intramuscular vasopressin injections raised serum-growth-hormone levels in fifteen children and adults of both sexes.” A third study [41] found that vasopressin had no effect upon human growth hormone.

Vasopressin is a hormone that regulates water retention, increases blood vessel constriction (leading to higher blood pressure) and helps balance water, glucose and salts in the blood.  It is produced by the hypothalamus and stored in the posterior pituitary.  It is typically extracted from the pituitary glands of pigs and cows, although I was unable to determine the source for this ingredient as used in GenF20Plus.

Phosphatidyl Choline (100 mg) The term “Phosphatidylcholine” is sometimes used interchangeably with the term “lecithin” although lecithin is a mixture of phosphatidylcholine and other compounds. Phosphatidylcholine is a major constituent of cell membranes.  The body uses phosphatidylcholine to produce acetylcholine, a brain chemical, thus there is interest in using it to treat certain brain disorders.  A review of clinical trials in humans found that there is not enough evidence to support lecithin or phosphatidylcholine supplementation for patients with dementia.[42]

Phosphatidylcholine is the primary active ingredient contained in cosmetic injection products that are intended to dissolve fat. However, in the U.S. when it is compounded and used as an injection, it is considered an unapproved drug rather than a dietary supplement.

“Phosphatidylcholine treatment alleviated high fat diet induced obese status and obesity-related complications such as hyperlipidemic changes that induce cardiovascular disease and Non-alcoholic fatty liver disease” in mice.[43]  Gut bacteria in the body metabolize phosphatidylcholine into choline, trimethylamine N-oxide (TMAO) and betaine.[44]  Various forms of choline have been shown to induce HGH release. [45][46][47]

L-Ornithine  (100 mg)  Arginine (see above) with ornithine supplementation increases growth hormone and insulin-like growth factor-1 serum levels after heavy-resistance exercise in strength-trained athletes. [48]


Synergies and Clinical Trial

If you have read this far,  you can see that most of the ingredients in  GenF20Plus and similar supplements have some basis in science.  What is unknown is how this particular combination of ingredients and doses affects humans in terms of HGH production and other factors.  Clinical trails are designed to gather this kind of information.  I was able to uncover a copy of a clinical trial that is mentioned on the GenF20Plus website. [49]

The objectives of the study were three-fold:

    • To assess the effect of the IP on the quality of life (with respect to libido, sleep, memory, energy, body weight) using a quality of life questionnaire as compared to placebo
    • To assess the safety and tolerability of the IP in study volunteers as compared to placebo
    • To assess the effect of the IP on IGF-1 levels as compared to placebo

There were 61 subjects with 31 receiving  GenF20Plus and the remainder receiving a placebo.  The study ran for twelve weeks. The study did not measure for a direct increase in HGH.

For those over age 40, that took  GenF20Plus, levels of IGF-1 rose by 22.69 ng/ml (28.57%) while those in the placebo group saw a reduction of 4.31 ng/ml (-0.55%).  There was no significant difference in IGF-1 levels among those under age 40.  This study shows clearly GenF20Plus will increase IGF-1 levels, and by extension HGH levels, in those over 40.

With respect to memory, energy level, and sleep, there was no significant difference between the GenF20Plus group and the placebo group.  Likewise, body mass index, waist circumference, body fat and lean body mass was not affected by GenF20Plus.  The authors stated: “The fact that serum IGF-1 levels have increased in 12 weeks, fosters the probability of improvement in all other parameters as well with consumption of GenF20 plus for longer duration.”

There were no adverse side effects.


My Conclusion

My conclusion was to give GenF20Plus a try for at least three months to see what effects I might experience.  I am not inclined to report my personal results because that would amount to a testimonial.  In my opinion, testimonials have no value other than to enhance or degrade the placebo effect  depending upon my conclusions.  I would much rather have you give the product a try without me introducing bias in your judgement.



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  1. What a great post! Thanks for sharing. I am currently taking another HGH supplement. I recognize some of the ingredients that you talked about that are in mine, but I will need to get the bottle to make a better comparison. I am always looking to try new things especially if someone else has had great results. I do appreciate the fact that you don’t want to share your results, because as you said it can act like a placebo. And anyone can say whatever they want regardless if its true or not. Thanks again for sharing so much valuable information!

    • Hi Tanya, Thanks for the kind words. If you want to give me the name of the supplement you are using, I’ll add info on it to the story.
      Best wishes,

  2. worried

    I would not take pituitary extract especially one not sourced due to the risk of prion related disease. Growth hormone was extracted from pituitary sources in the 80s and used for several years before a link with CJD was found.

  3. Jenny Le

    Hi, this supplement is safe for my 13 year old daughter to use? if using lower dosage? Thanks!

    • Hi Jenny Le,
      I did not research the safety of this supplement for kids. I suggest you ask the doctor that diagnosed your daughter as having growth hormone deficiency.

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