The pituitary gland is a structure in our brain that produces different types of specialised hormones, including growth hormone (also referred to as human growth hormone or HGH). The roles of growth hormone include influencing our height, and helping build our bones and muscles. Natural levels of growth hormone fluctuate during the day, seemingly influenced by physical activity. For example, levels rise when we exercise.
Most commonly, doctors prescribe synthetic growth hormone to help children who have impaired hormone levels to reach their full height.
However, there is a black-market trade in synthetic growth hormone, particularly among athletes, bodybuilders and those whose positive body image depends on looking muscular. These people may take growth hormone in the mistaken belief that it will boost their muscle strength. However, any improvement in muscle strength is actually due to other muscle-building substances commonly taken by athletes and bodybuilders, such as steroids.
How growth hormone works
Our bones need enough growth hormone during our childhood and adolescence in order to lengthen to adult proportions. Growth hormone prompts our liver to make a substance called insulin-like growth factor (IGF-1). This and other similar compounds are involved in bone growth.
Growth hormone for children
Some children lack sufficient natural growth hormone to grow to their full height. Taking a synthesised (artificial) hormone can help them reach the height that nature intended for them.
However, research suggests that a child with normal levels of growth hormone, who takes the synthesised version, will not grow any taller than nature intended. Healthy children who are given the synthesised version are at risk of serious disorders, including an immune system reaction against growth hormone.
For this reason, children who are experiencing stunted or slowed growth must have their natural growth hormone levels checked by medical professionals before they are prescribed any medications for their condition.
Acromegaly and growth hormone
Acromegaly is a disorder caused by excess levels of growth hormone, commonly as a result of a tumour in a person’s pituitary gland. It causes an irreversible overgrowth of bones, particularly those of the face, hands and feet. The person’s skin is also affected and becomes thick, coarse and hairy. Other side effects include high blood pressure and heart disease.
Long-term use of synthetic growth hormone can also cause acromegaly. This is because it is impossible for an adult to grow taller using synthetic growth hormone. The ends of the long bones (epiphyses) in the mature skeleton are fused. High doses of growth hormone can only thicken the person’s bones rather than lengthen them. Any increase in muscle size is actually due to an increase in connective tissue, which does not contribute to muscle strength.
Creutzfeldt-Jakob disease (CJD) and growth hormone
In the past, doctors used growth hormone taken from the pituitary glands of dead people. In some countries (not Australia), it was discovered that a progressive and incurable disease of the brain called Creutzfeldt-Jakob disease (CJD), which results in dementia and death, could sometimes be transmitted by this method.
Other chemicals used to increase muscle size
An athlete or bodybuilder who abuses growth hormone in an attempt to gain muscle size and strength is also likely to use other medications or illicit drugs to speed up their physical transformation. The dangers of mixing these different chemicals are not fully known.
Some of the substances people may use include:
- steroids - synthetic versions of the male sex hormone testosterone. These build muscle tissue and aid rapid recovery
- amphetamines - to aid in fat loss
- beta-blockers - to counteract trembling, a common side effect of steroids
- diuretics - to counteract fluid retention (by making the person urinate).
Treatment for abuse of synthetic growth hormone
Giving up synthetic growth hormone can be extremely difficult for adults whose positive body image depends on looking large and muscular. Some users continue to take the hormone, even though it is affecting their health and wellbeing.
Treatment options include counselling. See your doctor for information and referral, or contact an alcohol and other drug service in your area.
Where to get help
- Your doctor
- Alcohol and other drug service
- Australian Pituitary Foundation Tel. 1300 331 807
Things to remember
- Growth hormone is produced by our brain’s pituitary gland and governs our height, bone length and muscle growth.
- Some people abuse synthetic growth hormone in the mistaken belief it will help them increase muscle size and strength.
- Growth hormone abuse can cause an irreversible condition called acromegaly, which is the overgrowth of bones in the face, hands and feet.
This page has been produced in consultation with and approved by:
Hudson Institute of Medical Research
Page content currently being reviewed.
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