Insulin-like growth factor 1 (IGF-1) is a hormone produced mainly by the liver in response to growth hormone. It promotes cell growth, division, bone and muscle development, and tissue repair, and circulates bound to binding proteins. IGF-1 is essential for childhood growth and influences adult metabolism; abnormal levels indicate growth hormone disorders and are linked to certain cancers and metabolic conditions.

Insulin-like growth factor 1 (IGF-1) is a hormone, mainly produced by the liver in response to growth hormone, that mediates growth hormone’s effects. It stimulates cell growth, proliferation, differentiation and protein synthesis—especially in bone and muscle—supports tissue repair, inhibits apoptosis, and influences metabolism including glucose uptake. IGF-1 is crucial for normal childhood growth and adult tissue maintenance.

Low IGF-1 can cause poor growth and short stature in children, delayed puberty and recurrent hypoglycemia in infants. In adults it’s linked with fatigue, reduced muscle mass and strength, increased body fat, decreased bone density and higher fracture risk, low energy and exercise tolerance, low libido, mood changes (depression, poor concentration), and impaired wound healing.

Altered IGF‑1 levels occur in endocrine and chronic diseases: elevated in acromegaly and gigantism; associated with increased risks of certain cancers (breast, prostate, colorectal). Low IGF‑1 appears in growth hormone deficiency, malnutrition, chronic liver disease, aging, osteoporosis and cachexia. Abnormal IGF‑1 signaling is also linked to metabolic syndrome, insulin resistance, frailty and cardiovascular disease.

IGF‑1 supports growth, muscle and bone repair; normal levels are important for development and metabolic and anabolic health. However, chronically high IGF‑1 is linked to increased cancer risk (breast, prostate, colorectal), greater insulin resistance, and conditions like acromegaly. Abnormally low or high levels merit medical evaluation; management targets underlying causes and balancing benefits versus potential long‑term harms.

Foods that tend to raise IGF‑1 include animal proteins and high‑calorie diets. Dairy (milk, cheese, yogurt, whey), red meat, poultry, fish and eggs — and concentrated protein supplements — are most strongly associated with higher circulating IGF‑1. Higher overall protein and calorie intake increases levels; plant‑based proteins generally have a smaller effect.