— Research monograph
IGF-1 LR3
A long-acting analog of insulin-like growth factor 1 used in cell-culture research.
- Class
- Bioengineered IGF-1 variant with Long-R3 N-terminal extension (83 amino acids)
- Half-life (research)
- ~5–6 hr (vs ~10–15 min for native IGF-1 in preclinical models).
- Origin
- Developed at GroPep Limited (Adelaide, Australia) by Francis, Tomas, Wood, and colleagues in the early 1990s as a research tool with significantly extended half-life vs native IGF-1.
- Solubility
- Reconstitutes in dilute acetic acid (preferred for solubility) or bacteriostatic water.
What is IGF-1 LR3?
IGF-1 LR3 (Long R3 IGF-1) is a bioengineered analog of human insulin-like growth factor-1 carrying a 13-amino-acid N-terminal extension and an arginine substitution at position 3. The combined modifications dramatically reduce binding to IGF-binding proteins (IGFBPs).
Reduced IGFBP binding produces a substantially longer circulating half-life and higher receptor-available concentration than native IGF-1 at equivalent doses. The molecule is widely used in cell-culture research and preclinical anabolic-pathway studies.
How does IGF-1 LR3 work?
IGF-1 receptor agonist with potency comparable to native IGF-1 at the receptor itself. The pharmacological distinction lies in the LR3 variant's reduced affinity for IGFBPs (particularly IGFBP-3), which extends free hormone availability in circulation and at target tissues.
Research applications
- IGF-1 receptor pharmacology
- Cell-culture anabolic research
- IGFBP binding kinetics
- Comparative IGF-variant studies
Form & storage
IGF-1 LR3 ships as a sealed, lyophilized (freeze-dried) powder. Reconstitutes in dilute acetic acid (preferred for solubility) or bacteriostatic water. Store sealed, light-protected, and follow your institution’s handling procedures for research materials.
Frequently asked questions
What is IGF-1 LR3?
IGF-1 LR3 (Long R3 IGF-1) is a bioengineered analog of human insulin-like growth factor-1 carrying a 13-amino-acid N-terminal extension and an arginine substitution at position 3. The combined modifications dramatically reduce binding to IGF-binding proteins (IGFBPs). Merit supplies it as a lyophilized research compound for research use only — not for human or veterinary use.
How does IGF-1 LR3 work?
IGF-1 receptor agonist with potency comparable to native IGF-1 at the receptor itself. The pharmacological distinction lies in the LR3 variant's reduced affinity for IGFBPs (particularly IGFBP-3), which extends free hormone availability in circulation and at target tissues. Mechanistic descriptions summarize published preclinical findings and are not clinical claims.
What is the half-life of IGF-1 LR3?
~5–6 hr (vs ~10–15 min for native IGF-1 in preclinical models). Values reflect preclinical or research-context reports, not clinical pharmacokinetics.
Is Merit IGF-1 LR3 for human use?
No. It is sold strictly for research use only — not for human or veterinary use, and not for diagnostic or therapeutic use. Every lot ships with a certificate of analysis documenting ≥99% HPLC purity.
References
- Insulin-like growth factor (IGF)-I and especially IGF-I variants are anabolic in dexamethasone-treated rats. Tomas FM, Knowles SE, Owens PC, et al.. Biochemical Journal, 1992 · doi:10.1042/bj2820091
- Use of insulin-like growth factor I analogues for the study of receptor binding and biological effects in adipocytes. Francis GL, Ross M, Ballard FJ, et al.. Journal of Molecular Endocrinology, 1992 · doi:10.1677/jme.0.0080213
For research use only. Not for human or veterinary use. Not FDA-approved. Reference information summarized from published literature — not medical or dosing advice.