IGF-1 LR3

The Muscle and Tissue Builder | Modified Growth Factor Analog

What is IGF-1 LR3?

IGF-1 LR3 is a synthetic 83-amino acid analog of human insulin-like growth factor-1 that has never been approved for human use in any country. Despite approximately 3x greater potency than native IGF-1 with a 20-30 hour half-life due to reduced IGF-binding protein interaction, no human clinical trials have ever been conducted.

The Muscle and Tissue Builder IGF-1 LR3 is a long-acting version of "Insulin-like Growth Factor," a hormone that is essential for cell growth and repair. It is unique because it causes hyperplasia, meaning it actually helps create new muscle cells rather than just making existing ones larger.

Key Benefits

Approximately 3x more potent than native IGF-1 with 20-30 hour half-life due to reduced IGFBP binding. Promotes both muscle hypertrophy and hyperplasia in animal models.

New Muscle Cells: Promotes the creation of new muscle fibers for long-term strength.
Rapid Recovery: Drastically cuts down time needed to heal from intense physical strain.
Nutrient Shunting: Forces nutrients like protein and carbs into muscle cells rather than fat cells.
Nerve Repair: Supports the health and regeneration of nerves and tissues.
Increased Endurance: Improves the capacity for long-duration physical activity.
Fat Oxidation: Helps the body stay lean while in a muscle-building phase.

Quick Start Guide

Typical Dose

20-40mcg for beginners

How Often

Once daily post-workout

Where to Inject

Subcutaneous: abdomen, thigh, or upper arm

Injection Timing

Within 15-30 minutes post-workout with immediate carbohydrate intake

Effects Timeline

Initial: 1-2 weeks. Notable: 2-4 weeks. Desensitization: 6 weeks.

Storage

Reconstituted: 2-8°C

Cycle Length

4-6 weeks maximum

Break Between

Equal or longer off-cycle (4-6+ weeks) for receptor recovery

Research Indications

🟢 Muscle Growth - Most Effective

Muscle Hypertrophy

Animal studies show 15-20% lean mass gains in 4 weeks through satellite cell activation and protein synthesis enhancement. No human data exists.

Anti-Catabolic Effects

Preserves lean mass in cachexia models through ubiquitin-proteasome inhibition. Cancer cachexia rats maintained 30% more muscle versus placebo.

Hyperplasia Induction

Unique ability to create new muscle fibers via satellite cell differentiation, not just enlarging existing fibers. Permanent structural changes possible.

🔵 Tissue Repair - Effective

Wound Healing Acceleration

Promotes keratinocyte migration, epithelialization, and collagen synthesis. Mouse studies show faster wound closure and reduced scarring.

Ligament/Tendon Recovery

Rat MCL injury model showed improved maximum force and stress with enhanced type-I collagen expression. May overcome mechanical unloading effects.

Burn Recovery

Children with severe burns treated with native IGF-1 showed protein-sparing effects. LR3 variant untested in humans but theoretically more potent.

⚪️ Metabolic - Moderate

Nutrient Partitioning

Directs calories toward muscle rather than fat storage. Inhibits glucose uptake in adipocytes while promoting muscle uptake.

Fat Loss Enhancement

Promotes lipolysis and fatty acid oxidation independent of caloric deficit. Particularly targets visceral adipose tissue in animal models.

Insulin Sensitivity (Acute)

Short-term use may improve glucose uptake, though chronic exposure causes paradoxical insulin resistance through receptor downregulation.

What to expect

Week 1-2: Increased pump, fullness, possible hypoglycemia episodes if carbs inadequate
Week 2-4: Enhanced recovery, strength gains, visible muscle fullness, possible water retention
Week 4-6: Maximum effects but approaching receptor desensitization. Joint stiffness common.
Post-cycle: Gradual loss of pumps over 1-2 weeks. Strength/size gains may persist if training maintained.

Side Effects & Safety

Side Effects	When to Stop
CRITICAL: Consume 30-60g fast carbohydrates immediately after injection Never inject before sleep - overnight hypoglycemia risk Monitor blood glucose regularly, especially first week Contraindicated with any cancer history or undiagnosed growths May cause organ hypertrophy (heart, intestines) with prolonged use WADA prohibited - will cause failed drug test in athletes	Severe or recurring hypoglycemia despite carbohydrate intake Unusual growths, lumps, or rapid mole changes Severe joint pain or carpal tunnel symptoms Persistent nausea, headaches, or vision changes Signs of organ enlargement (abdominal distension) Extreme fatigue or mental fog

Side Effects

When to Stop

CRITICAL: Consume 30-60g fast carbohydrates immediately after injection

Never inject before sleep - overnight hypoglycemia risk

Monitor blood glucose regularly, especially first week

Contraindicated with any cancer history or undiagnosed growths

May cause organ hypertrophy (heart, intestines) with prolonged use

WADA prohibited - will cause failed drug test in athletes

Severe or recurring hypoglycemia despite carbohydrate intake
Unusual growths, lumps, or rapid mole changes
Severe joint pain or carpal tunnel symptoms
Persistent nausea, headaches, or vision changes
Signs of organ enlargement (abdominal distension)
Extreme fatigue or mental fog

Mechanism of Action & Molecular Information

Full IGF-1 receptor agonist with reduced IGF-binding protein interaction. N-terminal extension and R3 substitution prevent sequestration, maintaining free circulating levels. Activates PI3K/Akt/mTOR and MAPK/ERK pathways.

Weight	Length	Type
390.35 Da	4 amino acids	Tetrapeptide
Amino Acid Sequence:
Ala-Glu-Asp-Gly

References

Research Studies
Rat Muscle Hypertrophy Study (Florini et al.) `Sprague-Dawley Rats \| 2.5mg/kg/day \| 4 weeks \| 15-20% lean mass increase` Demonstrated 2.5x greater anabolic response compared to native IGF-1. Satellite cell activation and protein synthesis increased by 50% above baseline. Both hypertrophy and hyperplasia observed.
Fetal Sheep Metabolic Study (Children's Hospital Colorado) `Fetal Sheep \| 6.6μg/kg/h acute, 1.17μg/kg/h chronic \| 90 min to 1 week \| Study halted early` Acute infusion suppressed insulin secretion by 66%. Chronic infusion caused 4 animal deaths from hypoglycemia and hypoxemia. Significantly reduced circulating amino acids, particularly BCAAs.
Pig Growth Inhibition Study `Domestic Pigs \| 180μg/kg/day \| 4 days \| Paradoxical growth reduction` Contrary to expectations, decreased average daily gain and food intake. Reduced plasma IGFBP-3, IGF-1, and insulin. Growth hormone dropped 23% with 60% reduction in pulse area.
Guinea Pig Organ Study `Guinea Pigs \| 120μg/day \| 7 days \| No overall growth, organ-specific effects` No significant body weight gain or feed intake changes. Increased fractional weights of adrenals, gut, kidneys, and spleen. Suggests organ-specific rather than systemic growth effects.
Cancer Cachexia Rat Model `Tumor-bearing Rats \| 0.3mg/kg/day \| 14 days \| 30% lean mass preservation` Low-dose IGF-1 preserved lean mass during cancer cachexia, reducing loss from -41.4g to -28.8g versus placebo. Demonstrates anti-catabolic properties even in disease states.
Alzheimer's Mouse Model (5XFAD) `Transgenic Mice \| Intranasal LR3 \| 7 months \| Plaque remodeling without cognitive improvement` Improved body composition and reduced filamentous plaques in cortex. Increased inert plaques and reduced Aβ oligomers, but failed to improve cognitive symptoms. Highlights gap between cellular and functional outcomes.

Research Studies

Rat Muscle Hypertrophy Study (Florini et al.)

Sprague-Dawley Rats | 2.5mg/kg/day | 4 weeks | 15-20% lean mass increase

Demonstrated 2.5x greater anabolic response compared to native IGF-1. Satellite cell activation and protein synthesis increased by 50% above baseline. Both hypertrophy and hyperplasia observed.

Fetal Sheep Metabolic Study (Children's Hospital Colorado)

Fetal Sheep | 6.6μg/kg/h acute, 1.17μg/kg/h chronic | 90 min to 1 week | Study halted early

Acute infusion suppressed insulin secretion by 66%. Chronic infusion caused 4 animal deaths from hypoglycemia and hypoxemia. Significantly reduced circulating amino acids, particularly BCAAs.

Pig Growth Inhibition Study

Domestic Pigs | 180μg/kg/day | 4 days | Paradoxical growth reduction

Contrary to expectations, decreased average daily gain and food intake. Reduced plasma IGFBP-3, IGF-1, and insulin. Growth hormone dropped 23% with 60% reduction in pulse area.

Guinea Pig Organ Study

Guinea Pigs | 120μg/day | 7 days | No overall growth, organ-specific effects

No significant body weight gain or feed intake changes. Increased fractional weights of adrenals, gut, kidneys, and spleen. Suggests organ-specific rather than systemic growth effects.

Cancer Cachexia Rat Model

Tumor-bearing Rats | 0.3mg/kg/day | 14 days | 30% lean mass preservation

Low-dose IGF-1 preserved lean mass during cancer cachexia, reducing loss from -41.4g to -28.8g versus placebo. Demonstrates anti-catabolic properties even in disease states.

Alzheimer's Mouse Model (5XFAD)

Transgenic Mice | Intranasal LR3 | 7 months | Plaque remodeling without cognitive improvement

Improved body composition and reduced filamentous plaques in cortex. Increased inert plaques and reduced Aβ oligomers, but failed to improve cognitive symptoms. Highlights gap between cellular and functional outcomes.

Important Note
This content is intended for educational purposes only and is not medical advice, diagnosis, or treatment.

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