Do IGF-1 LR3 and IGF-1 DES differ from native IGF-1 in receptor binding?

Yes. Structural changes in LR3 and DES reduce their binding to IGF-binding proteins compared with native IGF-1, which can increase receptor availability and alter signaling dynamics. This makes them useful tools for dissecting IGF-1 receptor biology in research models.

IGF-1 Analogues: LR3 and DES Structural Variations and Receptor Binding in Research Models

Q: What are IGF-1 LR3 and IGF-1 DES in research?

IGF-1 LR3 and IGF-1 DES are synthetic analogues of native Insulin-like Growth Factor 1 (IGF-1). LR3 includes an extended N-terminal sequence and a substitution to reduce binding to IGF-binding proteins, while DES is a truncated form lacking the first three amino acids. Both are examined for modified receptor-binding and signaling in experimental models.

Q: How do IGF-1 LR3 and IGF-1 DES function in laboratory studies?

In preclinical research, IGF-1 LR3 shows reduced affinity for IGF-binding proteins and an extended half-life, allowing greater interaction with IGF-1 receptors. DES(1-3)IGF-1 has very low IGFBP binding and can display enhanced potency in certain tissue models. Both are used to study IGF-1 receptor signaling under controlled conditions.

Q: Are IGF-1 LR3 and IGF-1 DES considered therapeutic products?

No. IGF-1 LR3 and IGF-1 DES from The Peptide Company are provided strictly for laboratory and in-vitro research use. They are not therapies, drugs, supplements, or products for human or clinical use.

Q: What research applications involve IGF-1 LR3 and IGF-1 DES?

These analogues are used in studies of tissue-specific growth-factor signaling, receptor-binding kinetics, IGF-binding protein modulation, metabolic and endocrine pathways, and targeted cell-growth models in controlled laboratory settings.

Q: How are IGF-1 LR3 and IGF-1 DES typically stored and handled in research settings?

Both analogues are supplied as lyophilized powders, stored in a cool, dry place away from light. After reconstitution according to laboratory protocol, they are usually kept refrigerated and used only in designated in-vitro or institutional research workflows.

Q: Can IGF-1 LR3 or IGF-1 DES be administered or used by consumers?

No. IGF-1 LR3 and IGF-1 DES are not intended for self-administration or consumer use. They are reserved exclusively for controlled laboratory and in-vitro research environments.

Daniel Attalla
Nov 17, 2025
4 min read

3D molecular structure artwork of IGF-1 LR3 and IGF-1 DES shown in The Peptide Company’s charcoal and orange research branding

Introduction

Insulin-like Growth Factor-1 (IGF-1) is a central mediator of growth hormone (GH) signaling involved in tissue growth, cellular repair, metabolic function, and proliferation. Two widely examined analogues—IGF-1 LR3 and IGF-1 DES—help researchers study how structural modifications influence receptor activation, signaling duration, and tissue-specific responses. This article outlines IGF-1 biology followed by detailed sections on LR3 and DES, written strictly from a mechanistic, research-based perspective.

What Is IGF 1?

IGF-1 is a peptide hormone produced primarily in the liver in response to GH stimulation. It activates IGF-1 receptors (IGF-1R) and, to a lesser extent, insulin receptors (IR). Its downstream effects operate through the PI3K–AKT, MAPK, and mTOR pathways, influencing metabolism, survival, and growth. Because native IGF-1 is regulated by IGF binding proteins (IGFBPs), analogues offer a controlled way to study IGF-1R-specific activity.

LR3 IGF-1: Structural Modification and Extended Activity

IGF-1 LR3 features a 13-amino-acid N-terminal extension and a substitution of arginine at position 3. These modifications significantly reduce IGFBP binding, increasing receptor availability and extending activity. In research settings, LR3 allows long-duration IGF-1R stimulation and activation of PI3K-AKT, MAPK, and mTOR pathways under reduced IGFBP interference.

IGF-1 DES (1–3 IGF-1): Truncated Analogue With Enhanced Local Activity

IGF-1 DES lacks the first three amino acids of the IGF-1 sequence, further decreasing IGFBP binding. This analogue produces rapid and localized IGF-1R activation with a shorter activity period. Its strong local receptor affinity makes DES useful for studying tissue-specific IGF-1 effects and acute signaling responses.

Mechanistic Comparison

LR3 and DES share the same receptor target (IGF-1R) but differ in duration, IGFBP interaction, and tissue penetration. LR3 provides sustained receptor access and broad exposure, while DES offers intense, localized IGF-1R activation for shorter intervals. Both contribute complementary insights into IGF-1’s biological roles in controlled research environments.

IGF-1R Signaling Overview

IGF-1R engagement activates multiple intracellular pathways:• PI3K → AKT (survival, glucose metabolism) • RAS → MAPK (growth, differentiation) • mTOR (protein synthesis, anabolic signaling) • IRS-1/2 (insulin/IGF cross-talk)These pathways underpin IGF-1’s metabolic and growth-regulating effects in research models.

Summary

IGF‑1 analogues such as LR3 and DES help researchers examine how structural modifications influence receptor engagement, signaling intensity, and tissue specificity. LR3 provides sustained IGF‑1R signaling due to reduced IGFBP interaction, while DES offers rapid, localized receptor activation with a shorter half-life. Together, the analogues support comprehensive study of IGF‑1 pathway biology under different experimental designs.

LR3 vs DES: Mechanistic Comparison (Research Only)

Parameter	IGF-1 LR3	IGF-1 DES
Structure	13aa extension + Arg3 substitution	Truncated by 3 amino acids
IGFBP Interaction	Reduced	Strongly reduced
Receptor Activation	Sustained IGF-1R exposure	Rapid, localized IGF-1R activation
Research Focus	Extended signaling duration	Short-duration, high-intensity signaling
Half-Life	Longer activity window	Shorter activity window

Educational & Research Disclaimer

This article is for educational and research purposes only. No medical advice or product claims are made. These compounds are not approved for human use and are intended solely for laboratory research.

FAQ

Q1. What are IGF-1 LR3 and IGF-1 DES in research?

IGF-1 LR3 and IGF-1 DES are synthetic analogues of the native growth-factor peptide Insulin‑like Growth Factor 1 (IGF-1). LR3 includes added amino acids and a substitution to reduce binding to IGF-binding proteins, while DES is a truncated form (missing the first three amino acids). Both are studied for their modified receptor-binding profiles, bioavailability, and signaling activity in experimental models. PMC+2Wikipedia+2

Q2. How do IGF-1 LR3 and IGF-1 DES function in laboratory studies?

Research shows that LR3 has reduced affinity for IGF-binding proteins (IGFBPs) and a longer half-life, allowing increased receptor interaction and signaling effects compared to native IGF-1. PMC+1Similarly, DES(1-3)IGF-1 lacks the first three amino acids, exhibits markedly reduced IGFBP binding and enhanced potency in specific systems. Wikipedia+1

Q3. Are IGF-1 LR3 and IGF-1 DES considered therapeutic products?

No. The versions described here are for research use only by The Peptide Company. They are not approved therapies, supplements, or consumer products and are intended for controlled laboratory and in-vitro experimentation only.

Q4. What research applications involve IGF-1 LR3 and IGF-1 DES?

These analogues are used in experimental studies investigating tissue-specific growth-factor effects, receptor-binding kinetics, bioavailability outside IGFBP regulation, metabolic and endocrine signaling, and targeted cell-growth models. Frontiers+1

Q5. Do IGF-1 LR3 and IGF-1 DES have different receptor-binding profiles compared to native IGF-1?

Yes. LR3 has a longer chain and substitution that increases its resistance to IGFBPs and prolongs systemic availability. DES lacks the N-terminal three residues, giving it low IGFBP affinity and potentially higher localized potency in tissue models. Wikipedia+1

Q6. How are IGF-1 LR3 and IGF-1 DES typically stored and handled in research settings?

They are supplied as lyophilized powders, stored in dry, stable conditions away from light and extreme heat. After reconstitution according to lab protocol, they should be properly refrigerated and used only for designated in-vitro or institutional applications.

Q7. Can IGF-1 LR3 or IGF-1 DES be administered or used by consumers?

No. They are not for self-administration or consumer use. These analogues are strictly reserved for laboratory and in-vitro research environments and must not be marketed or used as therapies.

Related Research Compounds

Frag 176–191 — growth hormone-derived fragment & lipolytic pathways
Pancragen — pancreatic tissue bioregulation peptide
Bronchogen — bronchial/pulmonary tissue bioregulator
BPC-157 — tissue repair & regenerative peptide pathways

References (Selection)

PMID: 33587816 — Detection and characterization of IGF-1 analogues LR3 and DES in human serum PubMed

PMID: 10872804 — Insulin-like Growth Factor-1 survival mechanism and analogue binding (LR3 & DES) AHA Journals

PMID: 7913862 — Insulin-like growth factor-1 and its monitoring in research; includes LR3 variant discussion PMC

PMID: 16597689 — Mechanisms of tissue specificity and binding proteins in IGF analogues (DES variant studied) (excerpt) — you may want to verify for accuracy

PMID: 25828794 — Analogue binding-protein modulation and cell-growth specificity (extract from broader IGF analogue research) — you may want to verify