IGF-1 LR3

IGF-1 analog · lyophilized vial

$99per 1 mg vial · USD

IGF-1 LR3 (Long R3 IGF-I) is an 83-amino-acid analog of insulin-like growth factor 1 — C400H625N111O115S9, 9111.5 g/mol — with a 13-residue N-terminal extension and an arginine substitution at position 3. Those changes sharply reduce its binding to IGF-binding proteins, which is why it is used in cell-culture and animal research where an unbound, long-acting IGF-1 signal is wanted. APX Labs supplies it as a 1 mg lyophilized vial, ≥99% purity by HPLC/MS, with a batch-specific COA. Research use only.

Key facts

Class: IGF-1 analog — N-terminal extension + Glu3→Arg substitution
Formula: C400H625N111O115S9 · 9111.5 g/mol · 83 amino acids
Research contexts in the literature: IGF-binding-protein-independent potency, anabolic models, cell-culture growth factor
Format: 1 mg lyophilized vial — reconstitute with bacteriostatic water
Documentation: independent HPLC/MS test, batch-specific COA in every order

✦ COA included✦ Cold-chain shipping✦ Discreet packaging

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Specifications

Research category: Growth & Performance
Formula / short form: C400H625N111O115S9
Molecular weight: 9111.5 g/mol
Quantity per vial: 1 mg
Purity: ≥99% (HPLC/MS, per-lot COA)
Test method: HPLC / MS
Form: Lyophilized powder
Documentation: Batch-specific COA ships with every order

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What is IGF-1 LR3?

Native IGF-1 circulates almost entirely bound to IGF-binding proteins (IGFBPs), which limits how much is free to act on receptors. Long R3 IGF-I was engineered in the 1990s to bind those proteins poorly: the 'Long' refers to a 13-residue extension at the N-terminus, the 'R3' to the arginine that replaces glutamate at position 3. The result is an analog widely used as a cell-culture growth-factor supplement and in animal physiology research.

What is IGF-1 LR3 studied for in research?

Binding-protein-independent potency. Infusion studies compared IGF-I analogs that bind IGFBPs poorly and reported superior potency that was maintained over time [1].
Catabolic and body-composition animal models. LR3 IGF-I has been studied in models of weight loss under catabolic stress [2] and for the timing of IGF-I administration in anti-catabolic protocols [3].
IGF-1 signalling generally. Because IGF-1 acts on a receptor implicated in cell proliferation, its biology is also studied in oncology contexts [4] — a reason the compound is strictly a research reagent.

Laboratory and animal findings only — not claims of human effect.

Specifications, purity and documentation

Identity by mass spectrometry (expected ~9,111.5 g/mol), purity by HPLC, batch-specific COA in every order. A 1 mg vial is the standard research quantity for a protein of this size. How to read the COA →

IGF-1 LR3 — frequently asked

What is IGF-1 LR3?⌄

IGF-1 LR3 is an 83-amino-acid analog of insulin-like growth factor 1, modified to bind IGF-binding proteins poorly so that more of it is free and long-acting in laboratory systems. Research use only.

How is IGF-1 LR3 different from native IGF-1?⌄

It has a 13-residue N-terminal extension and an arginine replacing glutamate at position 3. Those changes reduce IGFBP binding and extend its studied half-life relative to native IGF-1.

Why is the vial only 1 mg?⌄

At ~9.1 kDa, IGF-1 LR3 is a small protein rather than a short peptide; 1 mg is the standard research quantity and is far more material by molecule count than a 1 mg vial of a small peptide would be.

References

Published research cited for context only. Citing a study does not imply APX Labs product was used in it, and is not a claim of any effect.

Tomas FM, et al. (1996). Superior potency of infused IGF-I analogues which bind poorly to IGF-binding proteins is maintained when administered by injection. J Endocrinol. PubMed ↗
Tomas FM, et al. (2001). Insulin-like growth factor-I (IGF-I) analogue, LR3IGF-I, ameliorates the loss of body weight. Growth Horm IGF Res. PubMed ↗
Tomas FM, et al. (1998). The anti-catabolic efficacy of insulin-like growth factor-I is enhanced by its early administration. J Endocrinol. PubMed ↗
Wetterau LA, et al. (2003). Insulin-like growth factor I stimulates telomerase activity in prostate cancer cells. J Clin Endocrinol Metab. PubMed ↗

[ Research context ]

What is IGF-1 LR3 studied for?

Referenced in cell-growth and metabolism research for its studied receptor affinity and extended half-life relative to native IGF-1.

[ Handling ]

Reconstitution & storage

Ships lyophilized in a sealed vial. Store cold and away from light. Reconstitute with bacteriostatic water (not included); once reconstituted, keep refrigerated and use within the window documented on the COA.

[ Compliance ]

Research use only

Sold strictly for laboratory and research purposes. Not for human or veterinary use, and not intended to diagnose, treat, cure, or prevent any disease. Not evaluated by the FDA. Read the policy → · What RUO means →