— 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
Handling & reconstitution
IGF-1 LR3 ships as a sealed, lyophilized (freeze-dried) powder and is reconstituted with bacteriostatic water for laboratory handling. Reconstitutes in dilute acetic acid (preferred for solubility) or bacteriostatic water. Concentration equals vial mass divided by diluent volume.
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.