What is Human Growth Hormone and its’ Functions

Human Growth Hormones and Functions

There is nothing more fulfilling than being able to comprehend how the functions in the human body are inextricably linked in a wonderful maze of systems – including nervous, cardiovascular and hormonal systems.

Although these systems are a wonder to fathom, the hormonal system is somewhat very impressive owing to the long-term effects it has on the body in general. Perhaps one of the most appreciated hormones in the human body in the Human Growth Hormone (HGH.)

📌What is HGH? Where is it produced? What are its constituents like? How does it work? What are its uses? The questions are numerous, but stay tuned for some compelling facts about the Human Growth Hormone.

HGH is a protein synthesized and secreted by cells called somatotrophs located in the anterior portion of the pituitary gland. It is composed of about 190 amino acids and is sometimes called somatotropin.

What makes HGH unique is that some people have turned to using it as a supplement in the hope of feeling healthy and looking young. Its role in improving an individual’s aesthetic value has been met with great success, making it one of the most widely used hormone supplements in the market today.

What Is the Function of Human Growth Hormone and What Does It Do

Function of Human Growth Hormone

Upon release from the anterior portion of the pituitary gland where it is produced, HGH is transported through the blood stream to its target tissues – chiefly the liver. To better understand the physiologic effects of growth hormone, it suffices to appreciate the concept that; it has two distinct types of effects: direct and indirect effects.

  • Direct effects of the Human Growth Hormone

The direct effects of HGH are achieved when this hormone binds directly to its receptors in the target tissue. The predominant direct action of HGH is manifested in the adipose tissue (where fat is stored in the body.)

The adipose tissue has receptors for growth hormone. As a result, this hormone bind to these receptors and mobilizes the breakdown of triglycerides (fat) to free fatty acids. This mechanism of action reduces the amount of fats stored in large body reserves such as in the belly, between the visceral organs.

  • Indirect effects of the Human Growth Hormone

The indirect effects of HGH are mediated primarily by another hormone called Insulin like Growth Factor 1 (IGF-1.) IGF-1 is synthesized by the liver and other tissues in response to growth hormone. Actually, the majority of growth hormone action is the body are mediated by IGF-1 when it binds to its receptors in the target tissues.

What does HGH do in the body

What does HGH do in the body

HGH uses both the direct and the indirect effects to influence growth and metabolic processes in the body.

HGH effects on growth

Growth is a very complex process which requires the coordinated action of several hormones – chief of which is growth hormone. Growth stimulation is one of the indirect effects of growth hormone. It achieves this effect by stimulating the synthesis of IGF-1 in the liver.

The consequent effects are as follows:

  • HGH on muscle: IGF-1 is a key player in muscle growth and developments. The cells forming muscular tissue are called myoblasts. IGF-1 enhances the differentiation of these muscles cells. 

The use of HGH supplements has increased significantly over the past few decades. Irrespective of how they are administered in the body, these supplements enter the blood stream and act either as secretagogues of GH or as analogues of GH.

IGF-1 also binds to its receptors and initiate cascades which ultimately stimulate protein synthesis in the muscular tissue. Generally, proteins are nutrients that help in body building. Rapid and well controlled protein synthesis in the muscles cause muscle hypertrophy which is highly beneficial in bodybuilding.

Since GH causes break down of fats directly, simultaneous loss of fat and muscle hypertrophy is exactly what a bodybuilder needs to stand out among several other contenders for massive muscles and formidable strengths.

  • HGH on bone: The growth of bones is mediated by cells known as chondrocytes which are also known as cartilage cells. By activating IGF-1, growth hormone causes the proliferation of these chondrocytes leading to increased growth and development of bones.

Some people use HGH supplements to boost their bone growth and the overall bone strength.

Enhanced bone strength is one of the indications for using HGH in bodybuilding, especially among athletes.GH also stimulates the proliferation of osteoclasts – the cells that resorb bone. As a result, it helps in maintaining a stable metabolic process in the bone which ensures that your bones remain constantly strong and healthy.

HGH effects on metabolism

Besides facilitating growth of both muscles and bones, HGH also influences quite a number of metabolic processes in the body. It is involved in the metabolism of the three major sources of energy, namely: carbohydrates, proteins and fats.

HGH is one of the hormones which serves to maintain blood glucose levels within a normal range. It is often referred to as insulin antagonists because it suppresses the ability of insulin to stimulate uptake of glucose by tissue. However, administration of HGH also stimulates the secretion of insulin.

📌HGH directly binds to its receptors in the adipose tissue to cause breakdown of fats into fatty acids. It also enhances protein synthesis particularly in the muscles. The major role played by HGH in metabolism and growth are what makes it a unique supplement in the medical arena.

Most supplement for HGH that are available in the market are not necessarily analogs of HGH. A majority are secretagogues made to enhance the synthesis and release of HGH from the pituitary. 

What Is HGH Used For

HGH Used ForIn 1985, the pharmaceutical industries achieved a great milestone by developing synthetic growth hormone for the first time. Shortly after development, it was approved by the food and drug administration for certain specific uses in adults and children. It was (and still is) approved for the medical treatment of short stature of unknown cause including poor growth.

Conditions that warrant the use of synthetic growth hormone to enhance better growth include:

  • Turner syndrome

Turner syndrome affects only females. It is a genetic condition which causes a variety of developmental anomalies such as short stature, cardiovascular defects, and poor development of reproductive structures particularly the ovaries. HGH is used for people with Turner syndrome to correct the short stature.

  • Prader-Willi syndrome

Prader-Willi syndrome is a rare genetic condition which causes physical, mental and behavioral problems. People with this condition presents with poor muscle tone, decreased levels of sex hormone and a constant feeling of hunger. Developmental anomalies are effectively treated with HGH.

  • Chronic kidney disease

When it occurs in children, chronic kidney disease is often associated with changes in the growth hormone and IGF-1 axis. This results in growth retardation. Sometimes, HGH is provided as a supplement to prevent growth retardation in chronic kidney disease.

  • Children born small for gestational age

Usually, some children are small for gestational age probably because their parents are small. In some cases, babies can be small for gestational age because they may be having growth problems that occurred during pregnancy. This condition is referred to as intrauterine growth restriction. Sometimes your doctor will prescribe GH therapy if your child is born with this condition. A gain of height is more dose dependent over the short time and less dose dependent over long term.

  • HGH insufficiency or total HGH deficiency

In children, GH deficiency is the most common pituitary hormone deficiency. It is often accompanied by the deficiency of other hormones produced in the pituitary. The consequence of this deficiency is an abnormal short stature, abnormal slow growth and certain levels of metabolic impairment. These anomalies are managed clinically with growth hormone supplementation.

In adults, specific medical use of growth hormone is indicated for conditions such as:

  • Severe muscle wasting diseases that is associated with HIV/AIDS
  • Treatment and hormone deficiency management in patient with pituitary tumors.

Despite the wide applications of growth hormone, most of its uses are not approved by the FDA. For instance, the most widely accepted use of HGH among athletes which is for building muscle and improving athletic performance has not been approved by the FDA.

Ideally, it has been proven that HGH supplementation is very effective for bodybuilding, owing to its effects on both muscle and bone development. However, its influence on the overall athletic performance is still not known. Other people also use GH supplements to reverse body deterioration that is related with age.

Although the FDA has not approved the use of HGH for anti-aging or for bodybuilding, you can obtain HGH supplements from off label prescriptions or from internet pharmacies, clinics and websites. Pills, sprays, drops and creams which are mainly secretagogues for growth hormone are also available for sale. Their mechanism of action is chiefly to stimulate synthesis and release of GH from the pituitary.

What Is HGH Levels

HGH LevelsIn a normal adult, the basal level of growth hormone concentration in blood is up to 300g/dl. The concentration is slightly low in children – about 500ng/dl. The total daily output of growth hormone in normal adults is 0.5 to 1.0mg. The half-life of circulating growth hormone is about 20 minutes and it is degraded by both the kidney and the liver.

The dosages of growth hormone usually vary depending on what it is being used for. When treating for GH deficiency in adults, a dosage of 1 to 3 IU per day is recommended. For bodybuilding, competitors always use dosages between 1 to 6 IU per day depending on what works better for them. Generally, 2 to 4 IU per day is the most common dosage because it is widely accepted to be both safe and effective. Therapy with these supplements can last for about 6 to 24 weeks.

Is HGH a Steroid?

Is HGH a SteroidThe era that was met with rapid advancements in bodybuilding was the 60s and the 70s. During this period, athletes were majorly using anabolic steroids such as testosterone to enhance their physique. Bodybuilding become very rampant, so much so that muscle enhancement products become synonymous to steroids.

However, in the 1980s, a revolutionary synthetic growth hormone was developed. It totally changed the approach to body building and humanity has never looked back since then.

Now, when questions are raised such as: is human growth hormone a steroid? The simplest answer is, No!

HGH is not a steroid. And here is a simple explanation:

Biochemically speaking, steroids are organic compounds that are synthesized from cholesterol. They include most hormones and certain vitamins. Steroid hormones that are often used in bodybuilding include testosterone. HGH on the other hand is a protein, synthesized from amino acids – not cholesterol.

What Triggers HGH?

What Triggers HGHThere are quite a number of factors that may trigger the release of HGH in the body. More often than not, the regulation of GH synthesis and release regulated physiologically. Some of the triggers of HGH include:

  1. Exercise

Exercise is highly metabolic and leads to the production of copious amount of lactic acid. Due it its metabolic nature, the hormone that is produced the most during high intensity exercise is growth hormone.

Exercise leads to a large spike of HGH because the muscles need energy during workout and GH is among the hormones that causes metabolism in muscles. If you want to increase growth hormone naturally, add intensity to your workout.

  1. Nutrition

It is not nutrition that influences the production of GH per se, but fasting and generally – hypoglycemia. Intermittent fasting is a strategy that is widely used by people who want to increase GH production naturally.

A regular but intermittent fasting significantly increases the levels of GH by reducing insulin levels or by reducing the total body fat. Reduction of both insulin and fat enhances GH production.Sleep

There is a common “myth” that children should sleep early because they grow at night. Well, this may not entirely be a myth but a scientifically proven fact. The pulsatile release of growth hormone form the pituitary usually peaks at night.

📌To enhance long term natural production of HGH, having a hood sleep is one of the strategies that you should not overlook. You may need to incorporate more strategies such as avoiding caffeine at night, avoiding blue light before bedtime, or having a pleasant bedroom just so that you can enjoy a peaceful night rest.
  1. Secretagogues and supplements

In the body, the hormone that stimulates the release of GH is called growth hormone releasing hormone (GHRH.) it is usually produced in the hypothalamus found in the brain. Most supplements for increasing the levels of GH are actually analogues of GHRH. The reason is simple: the synthetic production of GH is quite expensive.

This makes exogenous GH very expensive. Analogues of GHRH are cheaper to produce. Since GHRH is a releasing hormone which enhances the secretion of GH, these supplements are conveniently called secretagogues – because they also cause GH secretion.


📌Growth hormone is a very useful hormone, both physiologically and medically. Its effects on metabolism and growth has made it a common necessity among body builders and athletes. Although the FDA has not approved most of its uses, the results have always been impressive. Nevertheless, you should consult a professional before using GH supplements – especially when you want to use it for the first time.


  1. Rudman D, Feller AG, Nagraj HS Gergans GA, Lalitha PY, Goldberg AF, et al. Effects of human GH in men over 60 years old. N Engl J Med1990;323: 1-6
  2. Blackman MR, Sorkin J, Münzer T, Bellantoni M, Busby-Whitehead J, Stevens T, et al. Growth hormone and sex steroid administration in healthy aged women and men: a randomized controlled trial. JAMA2002;288: 2282-92
  5. https://www.ncbi.nlm.nih.gov/pubmed/15805349
  6. https://www.ncbi.nlm.nih.gov/pmc/issues/118434/
  7. https://www.ncbi.nlm.nih.gov/pubmed/26940392
  8. https://ghr.nlm.nih.gov/condition/prader-willi-syndrome
  9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2100434/


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