IGF-1 (Native)
Somatomedin C · IGF-1 · Insulin-like growth factor 1
The primary mediator of growth hormone's anabolic effects — a 70 amino acid peptide with structural similarity to insulin that promotes cell growth, protein synthesis, and tissue repair throughout the body.
Half-Life
~20 minutes (free IGF-1); ~15-16 hours (when bound to IGFBP-3/ALS ternary complex)
MW
7649.1 Da
Amino Acids
70 AA
Evidence
High Evidence
Regulatory Status
Mecasermin (Increlex, recombinant IGF-1) FDA-approved for primary IGF-1 deficiency (Laron syndrome). Prescription-only. Research-grade recombinant IGF-1 available for preclinical studies. IGF-1 LR3 (the commonly used research peptide) is a distinct compound from native IGF-1.
In Plain English
The main hormone that carries out growth hormone's instructions to the body. When your pituitary releases GH, your liver responds by making IGF-1 — which then tells your muscles to grow, your bones to lengthen, and your cells to divide and repair. It's why people measure IGF-1 levels to assess whether a GH-boosting peptide protocol is actually working.
Overview
IGF-1 (Insulin-like Growth Factor 1, formerly Somatomedin C) is a 70 amino acid single-chain peptide with three intramolecular disulfide bonds, structurally homologous to proinsulin. Produced primarily by the liver in response to growth hormone stimulation (endocrine IGF-1), and by virtually every tissue in response to local GH and mechanical stress (paracrine/autocrine IGF-1). IGF-1 is the primary mediator of GH's growth-promoting effects — the GH → liver IGF-1 → peripheral tissue axis drives linear growth, muscle anabolism, and organ development. Mecasermin (recombinant IGF-1, Increlex) is FDA-approved for GH-insensitivity syndrome (Laron dwarfism). Unlike IGF-1 LR3 (long R3 IGF-1, the research compound with a 13-AA N-terminal extension and Arg3 substitution), native IGF-1 has normal binding to IGF binding proteins (IGFBPs) which regulate its bioavailability. Serum IGF-1 levels are the primary clinical marker of GH status.
Common Formats
- Mecasermin solution for injection (clinical)
- Recombinant IGF-1 research grade (lyophilized)
Storage Notes
Refrigerate at 2-8°C. Do not freeze. In-use vials stable up to 30 days refrigerated. Lyophilized research peptide: -20°C long-term.
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Related Compounds
IGF-1 LR3
A potent long-acting variant of IGF-1 with a 13-amino acid extension and substitution that dramatically extends its half-life and prevents protein binding.
IGF-1 DES
A truncated, highly potent form of IGF-1 lacking the first 3 amino acids, with extremely short half-life and strong local anabolic effects.
PEG-MGF
A pegylated form of Mechano Growth Factor (a splice variant of IGF-1) with extended half-life and potent muscle satellite cell activation properties.
Tesamorelin
FDA-approved GHRH analogue specifically studied for visceral fat reduction in HIV-associated lipodystrophy, with broader anti-aging research interest.
Educational Disclaimer: All information on this page is for educational and research purposes only. This does not constitute medical advice, diagnosis, or treatment recommendation. Consult a qualified healthcare professional.