Table of ContentsView AllTable of ContentsProductionFunctionAssociated DisordersUse and BenefitsSide EffectsDoping and MisuseSafety
Table of ContentsView All
View All
Table of Contents
Production
Function
Associated Disorders
Use and Benefits
Side Effects
Doping and Misuse
Safety
Research has since determined that it is responsible for many other functions such as regulating sugar and fat metabolism, bone growth, and cellular regeneration. Some research even suggests that it may play a role in how the heart functions.
ajo888 / iStock / Getty Images
Human growth hormone consists of a single chain of 191 amino acids. It is made in the brain but secreted in the bloodstream.
The pituitary puts out HGH in pulsatile bursts that vary hourly. Higher daily hGH levels are seen after exercise, trauma, and sleep. Peak highest levels are reached at night. In general, HGH levels are increased in childhood, spike to their highest levels during puberty, and subsequently decrease as one ages.
HGH is mainly involved in two processes—growth and metabolism. HGH stimulates bone and cartilage growth, especially during periods of rapid growth during childhood.
Cartilage-forming and bone-forming cells called chondrocytes and osteoblasts receive signals to increase replication and thus allow for growth in size via HGH’s activation of the mitogen-activated protein (MAP) kinases designated ERKs (extracellular signal-regulated kinases) 1 and 2 cellular signaling pathways.
Activation of this phosphorylation intracellular signaling cascade results in a cascade of protein activation, which leads to increased gene transcription of the affected cells and ultimately causes increased gene replication and cellular growth.
Simultaneously, HGH upregulates insulin-like growth factor 1, which causes cells to increase amino acid uptake, protein synthesis, and decrease catabolism of proteins. This is the anabolic state.
Growth Hormone Disorders
Growth hormone disorders result from either too much or too little HGH. Hypersecretion of HGH from the pituitary leads to gigantism or acromegaly. HGH deficiency leads to short stature in children or GH deficiency syndrome in adults.
Acromegaly
Facial features include deep nasolabial furrows, prominent supraorbital ridges and enlargement of the nose and lips. Often the presenting complaint is of hats or gloves not fitting anymore due to swelling of the hands and head, although excessive sweating and headaches are also common.
If the mass gets large enough it can cause reproductive disorders and oraffect one’s vision. In addition to bony growth, HGH causes heart tissue to grow and harden in a process called biventricular concentric hypertrophy putting you at risk of heart failure.
Because HGH counteracts the effects of insulin on glucose and lipid metabolism, diabetes mellitus type 2 andhyperlipidemiaare strongly associated with this disease. Treatment consists of surgery and radiation therapy targeting the underlying adenoma as well as symptomatic relief of the secondary effects of HGH as above.
Acromegaly Overview and More
Gigantism
If the HGH from the underlying pituitary adenoma acts on the long bones before the growth plate of the long bone closes then gigantism results. Since epiphyseal closure occurs before adulthood, this is typically an illness with an onset seen in children. The organ and metabolic impacts are similar to acromegaly.
HGH Deficiency
In children, idiopathic HGH deficiency is most common. If HGH deficiency appears during adulthood it typically presents alongside a constellation of other hypopituitary deficiencies. A prolactinoma, a pituitary tumor that over-secretes the hormone prolactin typically triggers HGH deficiency, although radiation or surgery can be the culprit.
Adult-onset HGH deficiency is typically harder to diagnose than idiopathic HGH deficiency because the symptoms are nonspecific and no single identifying feature s pathognomonic.
Adults can have decreased skeletal muscle, increased belly fat, and early-onset osteoporosis. Dyslipidemia and insulin resistance are prevalent, which lead to secondary cardiovascular dysfunction, depressed mood, increased anxiety, and a lack of energy.
HGH induces growth in nearly every tissue and organ in the body. However, it is most notorious for its growth-promoting effect on cartilage and bone, especially in the adolescent years. Therefore, hGH is most often used to treat poor growth in children and adults.
Special blood tests can detect human growth hormone deficiencies in children and adults. Human growth hormone injections not only ameliorate short stature but also protects fractures, increases energy, improves exercise capacity, and reduces risk of future heart disease.
Up to 30% of those who take HGH experience side effects including:
HGH Doping and Misuse
Some athletes use recombinant human growth hormone (rhGh) to improve their athletic performance and get a competitive advantage. Taking rhGH not only increases muscle mass, but it also enhances recovery. The drug has been found in swimmers and also in players taking part in major sports events.
The World Anti-Doping Agency and the International Olympic Committee have had HGH on the list of forbidden compounds since 1989, when it became obvious that the development of biotechnology products based on the recombination of DNA made hGH much more easily available on the regular and black markets.
Sports leagues including Major League Baseball and the National Football League have also banned its use.
HGH Safety
As previously mentioned, HGH can have many adverse side effects. Also, HGH is injected intramuscularly or subcutaneously so there may be injury at the injection site. Lastly, HGH sold on the street can be laced with other drugs increasing your risk of experiencing a bad outcome.
HGH should only be taken under the watchful eye of a healthcare professional. If you are thinking about using HGH, consult a healthcare professional as HGH should only be taken for medical conditions that necessitate its use.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gupta V.Adult growth hormone deficiency.Indian J Endocrinol Metab. 2011;15 Suppl 3(Suppl3):S197-S202. doi:10.4103/2230-8210.84865Brinkman JE, Tariq MA, Leavitt L, et al.Physiology, growth hormone. StatPearls.Bartke A.Growth hormone and aging: Updated review.World J Mens Health. 2019;37(1):19-30. doi:10.5534/wjmh.180018Reed ML, Merriam GR, Kargi AY.Adult growth hormone deficiency - benefits, side effects, and risks of growth hormone replacement.Front Endocrinol (Lausanne). 2013;4:64. doi:10.3389/fendo.2013.00064Siebert DM, Rao AL.The use and abuse of human growth hormone in sports.Sports Health. 2018;10(5):419-426. doi:10.1177/1941738118782688
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gupta V.Adult growth hormone deficiency.Indian J Endocrinol Metab. 2011;15 Suppl 3(Suppl3):S197-S202. doi:10.4103/2230-8210.84865Brinkman JE, Tariq MA, Leavitt L, et al.Physiology, growth hormone. StatPearls.Bartke A.Growth hormone and aging: Updated review.World J Mens Health. 2019;37(1):19-30. doi:10.5534/wjmh.180018Reed ML, Merriam GR, Kargi AY.Adult growth hormone deficiency - benefits, side effects, and risks of growth hormone replacement.Front Endocrinol (Lausanne). 2013;4:64. doi:10.3389/fendo.2013.00064Siebert DM, Rao AL.The use and abuse of human growth hormone in sports.Sports Health. 2018;10(5):419-426. doi:10.1177/1941738118782688
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Gupta V.Adult growth hormone deficiency.Indian J Endocrinol Metab. 2011;15 Suppl 3(Suppl3):S197-S202. doi:10.4103/2230-8210.84865Brinkman JE, Tariq MA, Leavitt L, et al.Physiology, growth hormone. StatPearls.Bartke A.Growth hormone and aging: Updated review.World J Mens Health. 2019;37(1):19-30. doi:10.5534/wjmh.180018Reed ML, Merriam GR, Kargi AY.Adult growth hormone deficiency - benefits, side effects, and risks of growth hormone replacement.Front Endocrinol (Lausanne). 2013;4:64. doi:10.3389/fendo.2013.00064Siebert DM, Rao AL.The use and abuse of human growth hormone in sports.Sports Health. 2018;10(5):419-426. doi:10.1177/1941738118782688
Gupta V.Adult growth hormone deficiency.Indian J Endocrinol Metab. 2011;15 Suppl 3(Suppl3):S197-S202. doi:10.4103/2230-8210.84865
Brinkman JE, Tariq MA, Leavitt L, et al.Physiology, growth hormone. StatPearls.
Bartke A.Growth hormone and aging: Updated review.World J Mens Health. 2019;37(1):19-30. doi:10.5534/wjmh.180018
Reed ML, Merriam GR, Kargi AY.Adult growth hormone deficiency - benefits, side effects, and risks of growth hormone replacement.Front Endocrinol (Lausanne). 2013;4:64. doi:10.3389/fendo.2013.00064
Siebert DM, Rao AL.The use and abuse of human growth hormone in sports.Sports Health. 2018;10(5):419-426. doi:10.1177/1941738118782688
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
