Insulin-like Growth Factor (IGF-1)

What is Insulin-like Growth Factor?

Insulin-like growth factor is the most predominant somatomedin or growth factor hormone, with a very similar structure to insulin although it is released by the liver. It plays an important role in growth and development in children and is thought to have anabolic effects in adults.

Medical Uses of Insulin-like Growth Factor

Uses for IGF-1 in medical instances are rare, although it can be beneficial in the treatment of:

Dwarfism and other growth problems in children
Diabetes mellitus type 2
Kidney disease
Osteoporosis (condition resulting in reduced bone mineral density, also known as brittle bones)
Atherosclerosis (inflammation of the walls of the arteries)
Osteoarthritis
Myotonic muscular dystrophy

Effects on Performance

Due to perceived anabolic effects, athletes use IGF-1 to increase muscle mass and strength, although clinical studies have not shown any increases. It is thought that it is actually the IGF binding protein-3 which is responsible for growth rather than the growth factor itself. IGF-1 does, however, inhibit cell death and so may have a role in reducing recovery times.

Side-Effects of Insulin-like Growth Factor

Acromegaly in adult athletes (a condition where the pituitary gland produces too much hGH, resulting in the growth and swelling of body parts, typically hands, feet, nose but can progress to brow and jaw protrusion and swelling of internal organs)
Organomegaly (the abnormal enlargement of organs)
Hypoglycemia (lower than normal levels of glucose in the blood)
Cancer (prostate, lung and colorectal cancers have all been reported)