
IGF-1 LR3 is a long-arginine analog of insulin-like growth factor 1, modified for extended half-life and reduced binding-protein affinity. Supplied lyophilized and third-party verified.
| Purity | ≥99% (LC-MS verified) |
| Form | Lyophilized powder, preservative free |
| Storage | Cool and dry; refrigerate after reconstitution |
| Batch | COA available on request |
IGF-1 LR3 is a long-arginine analog of insulin-like growth factor 1, modified for extended half-life and reduced binding-protein affinity. Supplied lyophilized and third-party verified.
IGF-1 LR3 (Long R3 insulin-like growth factor 1) is an engineered analogue of human IGF-1, modified in two ways: an arginine substitution at position 3, and a 13-amino-acid extension at the N-terminus. Both changes serve the same purpose — reducing affinity for IGF-binding proteins.
Native IGF-1 circulates almost entirely bound to binding proteins, which regulate its availability. The LR3 modifications reduce that binding substantially, which extends the analogue's active half-life relative to native IGF-1 and is why it is preferred in research settings where sustained receptor exposure is required.
Supplied for laboratory research use only. Not for human consumption.
The defining property of LR3 is reduced affinity for IGF-binding proteins 1 through 6. Since these proteins normally sequester the majority of circulating IGF-1, reduced binding leaves more analogue available to engage receptors.
IGF-1 binds a receptor tyrosine kinase closely related to the insulin receptor, activating the PI3K/Akt and MAPK cascades — pathways central to cell growth, protein synthesis and survival signalling.
IGF-1 LR3 is widely used as a supplement in mammalian cell culture media, where its binding-protein resistance makes it more consistent than native IGF-1. This is one of its most established laboratory applications.
Animal and in vitro work has examined protein synthesis signalling in muscle tissue and glucose handling, reflecting the receptor's overlap with insulin signalling.
IGF-1 LR3 is a research reagent and cell-culture supplement. It is not an approved drug and has no approved human use.
Concentration is set by the volume of diluent added. For a 1mg vial, 1mL of bacteriostatic water yields 1mg/mL. Calculate the working concentration your protocol requires rather than following a generic figure.
| State | Temperature | Practical shelf life |
|---|---|---|
| Lyophilized, sealed | −20 °C | 24+ months |
| Lyophilized, sealed | 2–8 °C | ~12 months |
| Lyophilized, sealed | Room temperature | Weeks — transit only |
| Reconstituted, bacteriostatic water | 2–8 °C | ~3–4 weeks |
| Reconstituted, sterile water | 2–8 °C | Same session |
Lyophilized peptide is stable enough to survive shipping at ambient temperature, which is why cold-chain courier service is not required for transit. Long-term storage is a different matter — material intended to be held for months belongs in a freezer.
Protect from light, and avoid repeated freeze-thaw cycles. Each cycle causes measurable degradation, so dividing a reconstituted stock into single-use aliquots before freezing is preferable to thawing and refreezing one vial repeatedly.
Every lot is tested by an independent laboratory using two orthogonal methods. HPLC (high-performance liquid chromatography) establishes purity as a percentage of total peptide content, separating the target compound from truncated sequences and synthesis by-products. LC-MS (liquid chromatography–mass spectrometry) confirms molecular identity by mass.
Both matter. Purity alone is insufficient — a 99% pure sample of the wrong compound is still the wrong compound. Together the two tests establish identity and quality, which is why IGF-1 LR3 is released only after both pass.
The certificate of analysis references the lot number printed on your vial label. Request the COA for your lot at sales@pepsdepot.com.
Peer-reviewed studies indexed in PubMed. Each links to the abstract and, where a free copy exists, to the full text. We link primary sources rather than summarising them second-hand.
Compounds studied alongside this one, or acting through related pathways.
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