Peptide library / Bones & muscles / IGF-1 LR3
IGF-1 LR3
A modified IGF-1 with an 83 amino acid sequence used mainly in cell culture, sold for muscle growth.
Effects studied or claimed
What it is used or promoted for, and where each effect has actually been seen
- Cell growth in cultureLab
- Muscle growth, promotedLab
How it is thought to work
The changes reduce binding to proteins that normally restrain IGF-1, giving a stronger and longer-lasting growth signal.
What the evidence shows
It is a standard additive for growing cells in laboratories. There are no human therapeutic trials.
Safety and unknowns
IGF-1 signaling affects blood sugar and cell growth, so hypoglycemia and tumor promotion are theoretical risks.
Regulatory status
Not approved for human use. Banned in sport.
Regulatory status changes quickly. This entry was last reviewed on 27 October 2026. Confirm current status with the FDA before relying on it.
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General information, not medical advice. Do not buy or inject unregulated peptides.