IGF-1 LR3

IGF-1 LR3 (Long R3 Insulin-Like Growth Factor-1) is an engineered 83-amino-acid analogue of human IGF-1 incorporating two structural modifications: an arginine substitution at position 3 of the IGF-1 sequence and a 13-amino-acid N-terminal extension. These changes substantially reduce its affinity for insulin-like growth factor-binding proteins (IGFBPs), making it particularly useful in laboratory experiments where binding proteins might otherwise sequester native IGF-1 and limit receptor availability. FAB Research supplies IGF-1 LR3 in a 1mg pre-filled metered research pen for scientific investigation.

IGF-1 LR3 retains agonist activity at the IGF-1 receptor (IGF-1R), a receptor tyrosine kinase involved in regulating cellular growth, survival, differentiation and metabolism. Receptor activation initiates downstream PI3K/Akt signalling and MAPK/ERK signalling. The key research advantage is its reduced IGFBP affinity: in cell-culture experiments this increases the proportion available for receptor interaction compared with native IGF-1.

The primary literature is laboratory-based. Cell-culture studies have used the analogue to investigate IGF-1 receptor signalling, protein synthesis-associated pathways, cell proliferation and the role of IGFBPs in regulating growth factor availability. Evidence from cell-culture experiments does not establish increased muscle mass or any clinical benefit in humans.

• 1 mg total (single metered dose per pen)
• 1 dose per pen (1 mg total)
• 83-amino-acid IGF-1 analogue with reduced IGFBP affinity — key design difference from native IGF-1
• Pre-filled sterile solution — no reconstitution step required

Storage: Store refrigerated at 2–8 °C in the original sealed box. Do not freeze. Protect from light.

• For in-vitro laboratory and preclinical research only — not for human or animal administration
• Reduced IGFBP affinity is the primary research advantage over native IGF-1 — confirm this property is appropriate for the assay design; it also alters pharmacokinetic behaviour in in-vivo models
• No human clinical trial data exists specifically for IGF-1 LR3 — safety profile inferred from IGF-1 class pharmacology
• IGF-1R and insulin receptor share downstream PI3K/Akt and MAPK signalling — hypoglycaemia risk is a class effect; appropriate controls required

• No human clinical trial data exists for IGF-1 LR3 specifically
• IGF-1 class pharmacology: hypoglycaemia risk — insulin receptor cross-reactivity at the signalling level is documented
• Headache, fatigue, myalgia — documented in research contexts for the IGF-1 receptor agonist class
• Water retention consistent with IGF-1 receptor activation (sodium retention, renal effects)
• Tumour promotion risk: IGF-1R signalling is a recognised driver of cellular proliferation — relevant consideration for cancer cell line experiments

Effects listed are observations from published research literature and are not predictions for any specific use. All FAB Research products are for in-vitro laboratory research — not for human or animal administration.