IGF-1
Also called: insulin-like growth factor 1
What it means
IGF-1, or insulin-like growth factor 1, is a substance in your body that protein intake stimulates, helping to support both muscle and bone health.
Getting enough protein helps stimulate IGF-1, which supports the muscle and bone health that keep you strong and steady as you age.
IGF-1 stands for insulin-like growth factor 1. It's a growth factor in your body that gets stimulated when you eat enough protein, and it plays a role in supporting both muscle and bone.
Because about 35% of bone mass is actually made of collagen, a protein, getting enough protein in your diet matters for bone health. Research has linked low protein intake to lower bone density and a higher risk of fractures, especially as people get older. Protein's connection to IGF-1 is one reason it supports bone, alongside its direct role as a building block for bone tissue.
You may have heard that eating a lot of protein causes your body to lose calcium. That idea has largely been disproven. In fact, when calcium intake is adequate, higher protein diets are now linked to better bone health rather than worse.
How sure is this?
Graded Established Science: Supported by broad scientific consensus and decades of research. Read each study with its grade in mind. One study is a piece of the picture, not the whole of it.
Where the Academy teaches it
This page is the short version. The lessons teach it in full, with the context around it and a quiz to lock it in.
Related words
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Sarcopenia is the gradual loss of muscle mass and strength that comes with aging, and it's closely tied to bone health.
Education only, not medical advice. Decisions about tests, medications and treatment belong with your own doctor. OsteoStrong does not diagnose, treat or cure any disease.
