What is growth hormone as a drug?

In one line

Growth hormone as a drug is a medicine made almost identical to the body's own growth hormone, originally used to treat people who lack it.

What is growth hormone as a drug?
Why does a medicine come up in gym talk?
Growth hormone is used as a medicine for children who do not grow well. Yet it also comes up often in talk about muscle drugs, alongside steroids. What is growth hormone as a drug, and what does it do in the body?
In short
A medicine made to match the body's growth hormone
Growth hormone as a drug is a medicine made in almost the same shape as the growth hormone the body makes. It was meant to treat people who lack growth hormone. Using it without a prescription to build muscle or lose fat is 'misuse', using a drug the wrong way.
What is growth hormone?
A hormone from a small organ below the brain
A hormone is a substance made in one part of the body that travels through the blood and sends a signal elsewhere. Growth hormone comes from the 'pituitary gland', a pea-sized organ attached to the underside of the brain. In childhood it makes you grow taller, and in adults it keeps coming out to control muscle, bone and fat.
How it works
It makes the liver produce IGF-1
When growth hormone reaches the liver through the blood, the liver makes another hormone called 'IGF-1'. It is mainly IGF-1 that actually makes bones and body tissues grow. So much of what growth hormone does happens by way of IGF-1.
Fat and muscle
It draws on fat and spares protein
Growth hormone makes the body take stored fat out and burn it for energy. At the same time, it makes the body use less of its protein, such as muscle, and save it. That is why adults who lack growth hormone lose muscle and gain belly fat.
How the drug is made
From human glands to biotechnology
In the past, growth hormone was extracted from the pituitary glands of people who had died. But some people who received it developed 'Creutzfeldt-Jakob disease', an incurable brain disease, and supply was stopped in 1985. Today the drug is 'recombinant growth hormone' made with biotechnology, which carries no risk of passing on that disease.
Medical use
A treatment for people who lack growth hormone
Recombinant growth hormone is used to treat children who do not grow well because they lack growth hormone, and adults who lack it because of pituitary disease and other causes. Doctors confirm the lack with blood tests before prescribing it. In adults who lack it, it brings back lost muscle and reduces gained fat.
Why people who work out use it
To add muscle and lose fat
Some people who work out use growth hormone without a prescription to build muscle and lose fat. It is often used together with anabolic steroids. In sport, the World Anti-Doping Agency lists growth hormone as a banned drug. In trials giving it to healthy young people, weight other than fat went up, but strength showed no difference from people not given it.
Side effects
Swelling, joint pain, numb hands
People given growth hormone had swelling more often than people not given it. Muscle and joint pain and heavy sweating have also been reported. It also causes 'carpal tunnel syndrome', where a squeezed nerve in the wrist makes the hand numb, and diabetes, where blood sugar runs high.
When there is too much
Risks mostly inferred from acromegaly
A disease in which the body makes too much growth hormone for a long time is called 'acromegaly'. The hands, feet, jaw and nose get bigger, and diabetes, high blood pressure and heart disease develop. The risks of using large amounts of growth hormone as a drug are mostly described based on what this disease has shown.
Common misconception
Is it only used by people who compete?
No. Public attention goes to drug cases at famous sporting events, but most people who use muscle drugs are ordinary gym-goers building their bodies with no connection to competition. Growth hormone is also used among gym-goers who never compete.
Summary
A medicine made to match the body's growth hormone
Growth hormone as a drug is a medicine made almost identical to the body's own growth hormone, originally meant to treat people who lack it. It is also used without a prescription by ordinary gym-goers who do not compete. Related terms: growth hormone, IGF-1, acromegaly.