IGF-1 LR3

IGF-1 LR3 is presented here as a laboratory catalogue entry for research environments that need clear identification, labelled variants, and direct access to supporting records. The current listing includes 2 labelled variants: 0.1mg and 1mg. That structure keeps the page useful as both a procurement reference and an indexable resource covering stock visibility, pricing context, and documentation.

Within the wider Au Peptide Labs catalogue, IGF-1 LR3 sits alongside TA-1, Melanotan 1, and Retatrutide. Researchers often review neighbouring compounds before selecting a comparator or deciding which sequence belongs in a screening panel. Keeping those internal paths close to the product page improves traceability and helps laboratory buyers compare materials without relying on vague or consumer-style copy.

In research literature, IGF-1 LR3 is generally treated as an engineered 83-amino acid IGF-1 analog (Long-R3-IGF-1) with an Arg3 substitution and a 13-amino acid N-terminal extension that reduces insulin-like growth factor binding protein (IGFBP) affinity by approximately 500-fold. IGF-1 LR3 retains near-native binding affinity for the IGF-1 receptor (IGF-1R) — a receptor tyrosine kinase that autophosphorylates on ligand binding and recruits IRS-1 for PI3K/Akt and Grb2-SOS for MAPK/ERK activation — but bypasses IGFBP-mediated sequestration in cell culture medium. This dramatically extends its effective half-life in serum-containing assay systems relative to native IGF-1, making it the preferred choice for cell-based proliferation, differentiation, and survival assays where IGFBP-3 and other binding proteins would otherwise limit bioavailability. The Arg3 substitution specifically reduces IGFBP-3 binding without substantially altering IGF-1R kinetics.

The IGFBP bypass property is both the main experimental advantage and a design consideration — cell assays using IGF-1 LR3 are not directly comparable to assays using native IGF-1 because IGFBP buffering is absent. Researchers studying the modulating role of IGFBPs often deliberately compare LR3 against native IGF-1 to attribute differences in downstream readouts to IGFBP interference. For laboratory teams, the practical emphasis is usually on sequence identity, receptor or pathway relevance where documented, and whether IGF-1 LR3 behaves consistently across stability, purity, and analytical verification workflows. Variant labels on this page support clearer internal referencing when multiple labelled variants are under review.

If a product-specific file is not attached to this listing, the wider COA library remains the correct reference point for current published documentation. The COA section is useful for confirming how the product is labelled in the catalogue, whether purity information has been published, and whether the laboratory record for the material is complete before bench use.

When teams compare IGF-1 LR3 with TA-1, Melanotan 1, and Retatrutide, COA access also helps keep comparator decisions grounded in documented material identity rather than assumption. That is especially important for research pages that combine pricing, variant selection, and analytical records on a single URL.