What is HGH?

In this article, you will find the information about the scientific basis of HGH work: HGH structure, functions, effects on the body, and how you can benefit from it.

We hope that this information will be useful for you both theoretically and practically.

What is HGH scientifically?

Human growth hormone (HGH) is a 191-amino acid, the hormone which is secreted by the anterior pituitary. Growth hormone is involved in many body processes during the whole life. It promotes the growth of bones, regeneration of skin, muscle growth and loss of fat. Also, HGH participates in the nutrient metabolism of proteins, fats, and carbohydrates.

Recombinant human growth hormone (rHGH) is a synthetic type of this hormone. Synthesized in 1985, rHGH is produced by the bacterium E.coli, which is genetically changed.

Human growth hormone that circulates in the body has more than 100 forms of different weight and quality. 22-kDa isoform constitutes 20% of all HGH.

The molecule of HGH has the peptide structure and consists of 20 types of amino acids.

How is HGH produced?

Growth hormone is controlled by two processes, synthesis and secretion, which don’t coincide. HGH synthesis in the pituitary is a permanent process which continues the whole day on the same level when its secretion has the pulsatile nature. Secretion of growth hormone is regulated by 2 hormones, somatoliberin and somatostatin, which have opposite natures. The first one deliberates HGH, while the second hormone blocks the deliberation. During the day, their balance changes, and GH is secreted into the bloodstream.

Both somatostatin and somatoliberin are secreted by the hypothalamus and bound to receptors of somatotropic cells in the pituitary, thus regulating HGH secretion.

How does HGH work?

Growth hormone influences the body both by itself only and through so-called somatomedins – A, B, C.

IGF-1 has significant anabolic effects. Most of the HGH effects,  including the muscle growth, fat burning, healing of injuries, muscle cell division, are performed by the IGF-1.

It is produced mostly by the liver, and, in low amounts, by muscle, bone, and skin tissue. Then IGF-1 circulates to tissues and enhances their growth.

IGF-2 (insulin-like growth factor) is responsible for child growth before birth. IGF-2 divides body cells, including muscle and bone cells. Researchers have discovered [1], that IGF-2 local injections stimulate bone development.

Vitronectin – its functions haven’t been fully discovered yet, but the research shows that vitronectin is likely to have some anabolic functions.

Also, GH influences body on its own, by increasing metabolic velocity (REE) by 20%, which is useful for fat loss [2].

What are HGH effects?

  • Accelerates muscle protein synthesis, which leads to muscle growth.
  • Prevents proteins and amino acids breakdown – catabolism.
  • Helps to burn fat, increasing the level of FFA (free fatty acids).
  • Increases bone mineral density.
  • Accelerates collagen and elastin synthesis, thus healing cartilage and improving skin.
  • Improves the immune system.
  • Diminishes the extra cholesterol in the blood.
  • Improves the cardiovascular system.

What is HGH secretion dynamics?

GH secrets in a pulsating way as every 3-5 hours its level increases from 1 up to 5-10 ng/ml. The highest peak is observed in first hours of the night when 70 % of the GH daily amount is secreted.

HGH level decreases with age. The process of HGH diminishing runs since birth and continues until death. The most dramatic decrease is observed when a person reaches 30. In this age, many people begin to experience symptoms of GH deficiency. The pituitary of a teenager secrets 2 mg (about 6 IU) of HGH each day, this level decreases to 0,75 mg (2 iu) at 20, and to 0,2 mg at the early forties.

The number of daily secretions decreases as well – from 8 to 4 with age. The decrease of HGH is connected with changes in appearance, such as the loss of muscle mass, fat gaining, or occurring of wrinkles.

Ways to increase your HGH


As the highest peak of GH is observed during the first hour of sleep, you need to sleep well

  • Form a stable schedule of going to bed. Retire for the night and wake up at the same time every day.  It will help your pituitary and whole organism work better.
  • Don’t go to bed later than at midnight. The optimal time time to fall asleep is 10-11 PM. Delayed sleep isn’t so effective in GH secretion. For example, if you fall asleep at 10 PM, your peak will be about 30 ng/ml instead of 10 if you do it 3 AM.
  • Avoid sleep interruptions. Interruptions, even if they are short, don’t allow your growth hormone to secrete well.
  • Try to have a nap during the daytime
  • Keep distractions from your bed. When we use a bed for reading, surfing the Net, or listening to music, we change the psychological perception of the bed. It worsens the ability to fall asleep quickly.
  • Sleep in a dark room. Light destroys melatonin, the hormone of sleep. So, if you want to sleep deeper and better, keep any light out of your room
  • Don’t eat sweet and fatty food before going to bed. Sugar induces insulin production, which, in turn, blocks secretion of HGH. Fatty food has the similar effect because it is also hard digest, which affects your sleep

What is HGH response to resistance exercises?

There are many studies about exercises and GH secretion. Kraemer and Godfrey [7,10] have conducted several experiments to explore growth hormone response on different heavy-resistance exercise protocols. The factors they examine include the exercises heaviness, number of exercises and sets, duration of each set, rest time between sets.

Based on these experiments, we can outline training principles for GH secretion:

  • Basic exercises induce better hormonal response than isolated ones,
  • High volume training is better than low volume one. Big number of sets and short pauses between them is great for HGH
  • Do 40-50 sets during 1-1,5 hours.
  • Don’t eat carbohydrates within 30 minutes after training, when HGH level is high.

What is HGH response to aerobic?

The experiment by W.M. Hunter [9] has proved that aerobic exercises can greatly increase HGH secretion up to 40- 100 ng/ml (look at the pic), which is higher than the average daytime level by 8-20 times! It is caused by the high level of fat acids observed during the aerobic workout, which sends a signal to the pituitary to secrete growth hormone for utilization of the fatty acids.

Methods to induce growth hormone secretion include:

  •  The optimal time for aerobic is 1 hour. Most of HGH is released during this period.
  • Don’t eat carbs one hour before jogging.
  • Protein consumption before jogging can increase HGH level, but fat burning will be harder in this case.
  • Do it in the morning when the level of blood sugar is low.

What forms of growth hormone exist?

  • Pills and capsules. It isn’t HGH in the original meaning because growth hormone gets destroyed in the stomach without giving any effects. Pills and capsules contain special secretagogues that help the organism to produce its own HGH. The most common ingredients are arginine, ornithine, and other amino acids that can increase HGH. However, the price for such products is 5-10 times higher than the real price of their ingredients.
  • HGH sprays and patches. It’s the similar story. There are only 2 differences: way of use and price.  While we eat HGH pills and they are digested in the stomach, HGH spray is taken sublingually, i.e. spray under a tongue, where capillaries absorb the substance into the bloodstream. HGH sprays cost even more than HGH pills because of their more respectable form.

HGH patches don’t have a clear mechanism of action. They seem to be a kind of scam.

  • HGH injections. It is the only possible form of real growth hormone. The hormone can be injected intramuscularly and subcutaneously. The second variant is more effective. rHGH is completely the same as original human growth hormone. However, it contains bacterial residue, and if purity of growth hormone is low, it can cause immune response

What is HGH used for?

Although synthetic growth hormone was created to treat children who suffer from GH deficiency, now the main scope of HGH usage is health: anti-aging therapy and sport.

After HGH had been discovered, it rapidly became popular in bodybuilding due to its strong anabolic effects, such s muscle gain, muscle cells division, fat burning. Growth hormone is a philosopher’s stone for bodybuilding because it builds muscles and burns fat at the same time.

For bodybuilding purposes, HGH should be used at least for 2-3 months to witness a significant change in the body composition. The optimal dosage ranges depending on the purpose, weight and athletic experience, between 4 and 20 ius. 4-8 ius dosage provides significant fat burning effect, but the optimal dosage for muscle gains starts from 10 IUs daily.

HGH half-life period is 4-6 hours, and thus daily dosage needs to be divided into 3 injections with equal pauses. The optimal administration is an injection in the morning and the next one 6 hours later.

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1) http://ghr.nlm.nih.gov/gene/IGF2

2) Derek Le Roith, Carolyn Bondy, Shoshana Yakar – The Somatomedin Hypothesis: 2001

3)   D M Shinar, N Endo, D Halperin – Differential expression of insulin-like growth factor-I (IGF-I) and IGF-II messenger ribonucleic acid in growing rat bone

4) R R Davies D G Johnston – Growth hormone releasing factors

4)   Helen Robso n, Thomas Siebler, Stephen M Shalet – Interactions between GH, IGF-I, Glucocorticoids, and Thyroid Hormones during Skeletal Growth

5)   Christian Jux, Kathrin Leiber, Ulrike Hügel – Dexamethasone Impairs Growth Hormone (GH)-Stimulated Growth by Suppression of Local Insulin-Like Growth Factor (IGF)-I Production and Expression of GH- and IGF-I-Receptor in Cultured Rat Chondrocytes

6)   Len Kravitz, Ph.D. and Lance Dalleck, Ph.D. – Lactate Theshold Training

7)   William J. Kraemer, Keijo Häkkinen, Robert U. Newton – Effects of heavy-resistance training on hormonal response patterns in younger vs. older men

8)   Craig BW1, Brown R, Everhart J. – Effects of progressive resistance training on growth hormone and testosterone levels in young and elderly subjects.

9)   Hunter W. M. Fonseka C. C. and; Passmore R – the role of growth hormone in the mobilization of fuel for muscular exercise

10) William J. Kraemer and Nicholas A. Ratamess – Hormonal Responses and Adaptations to Resistance Exercise and Training