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IGF-LR3

Long-acting insulin-like growth factor — muscle growth and recovery

4.5
2 reviews
Rate This Peptide

Rating Breakdown

Muscle Hypertrophy
5.0
Satellite Cell Activation
4.5
Recovery Speed
4.5
Strength Gain Support
4.5
Extended Half-Life
4.0
Safety & Side Effects
2.5

Overview

IGF-LR3 is a modified version of insulin-like growth factor 1 (IGF-1) with an extended half-life for sustained muscle-building effects.

Key Information

Identity
Also Known As Long R3 IGF-1; IGF-1 LR3
Sequence Modified IGF-1 with Arg-3 substitution and 13-amino acid extension
CAS Number 143045-27-6
Molecular Formula C330H518N94O101S7
Properties
Half-Life ~20 hours
Administration subcutaneous injection, intramuscular
Dosage Range 20-50 mcg daily
Price Range $1.0–$10.0/mg
Handling & Storage
Storage Lyophilized: -20C; Reconstituted: 2-8C
Reconstitution Reconstitute with acetic acid or bacteriostatic water
Regulatory Status
US Status Research only
Research Papers 5 indexed

Mechanism

Binds to IGF-1 receptors to promote muscle protein synthesis, satellite cell activation, and muscle hypertrophy. LR3 modification extends half-life to ~20 hours.

Benefits

  • Muscle hypertrophy
  • Enhanced recovery
  • Satellite cell activation
  • Extended half-life (LR3)

Side Effects

  • Hypoglycemia risk
  • Organ growth concerns at high doses
  • Injection site pain

Contraindications

  • Active cancer
  • Diabetes (hypoglycemia risk)

Evidence Summary

Studies show significant muscle hypertrophy and improved recovery compared to GH.

Research

Studies show significant muscle hypertrophy and improved recovery. Often compared to growth hormone effects.

View Research

Safety

Potential for hypoglycemia. Organ growth concerns at high doses.

Frequently Asked Questions About IGF-LR3

What is IGF-LR3?

IGF-LR3 is a research peptide also known as Long R3 IGF-1; IGF-1 LR3. Long-acting insulin-like growth factor — muscle growth and recovery It is studied for its potential therapeutic applications and is available from various research chemical vendors.

How does IGF-LR3 work?

Binds to IGF-1 receptors to promote muscle protein synthesis, satellite cell activation, and muscle hypertrophy. LR3 modification extends half-life to ~20 hours.

What is the recommended dosage for IGF-LR3?

The commonly studied dosage range for IGF-LR3 is 20-50 mcg daily. Dosage protocols vary based on research objectives. Always consult published studies and start with conservative amounts. IGF-LR3 should only be used in controlled research settings.

Where can I buy IGF-LR3?

PepsReview indexes IGF-LR3 pricing from multiple vendors. Check the Vendors tab above for a price comparison table showing cost per milligram, purity, COA status, and stock availability. Vendor reviews from real users are available on each vendor's profile page.

Is IGF-LR3 legal?

US regulatory status: Research only. The legal status of IGF-LR3 varies by jurisdiction. In most countries, it is sold as a research chemical, not for human consumption. Always verify the legal status in your country before purchasing.

What are the side effects of IGF-LR3?

Reported side effects include: Hypoglycemia risk, Organ growth concerns at high doses, Injection site pain. Always review safety data and published studies before use.

Key Research Papers on IGF-LR3

The following peer-reviewed studies and clinical trials are indexed in our research library for IGF-LR3. Each paper links to a detailed summary with key findings, study design, and publication metadata.

Related Muscle growth / Anabolic Peptides

Other peptides in the muscle growth / anabolic category that may be of interest for comparative research:

No vendor prices yet

We don't have pricing data for this peptide yet.

Research

5 research papers indexed

View Research

Write a Review

Rating Breakdown

Effectiveness
5.0
Overall
4.5
Value
4.0
Safety
2.5

Based on 2 reviews.

Reviews

Serious muscle growth 2026-06-28
Jessica F. Top Reviewer

IGF-LR3 is the most potent muscle-building peptide I've used. Hypertrophy is noticeable within 2 weeks. Recovery between workouts is dramatically faster. The extended half-life of LR3 makes it superior to regular IGF-1. Handle with respect - this is powerful.

Effectiveness: 5/5 Safety: 3/5 Value: 4/5
Great for advanced trainees 2026-06-13
Robert D. Top Reviewer

IGF-LR3 delivers on muscle growth. Pump is incredible, recovery is fast. The LR3 variant lasts 20-30 hours which is much better than DES. Need to be careful with blood sugar - can cause hypoglycemia. Not for beginners.

Effectiveness: 5/5 Safety: 2/5 Value: 4/5