IGF-1 LR3
Modified Growth Factor Analog | Research Chemical Only
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 compound is prohibited in competitive sports, carries significant risks including severe hypoglycemia and cancer proliferation, and remains strictly a research chemical for laboratory use only.
Daily dose
20-100mcg (research range)
Frequency
Once daily
Cycle length
4-6 weeks maximum
Storage
-20°C to -80°C (lyophilized)
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.
How it works
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.
Dosage protocols
Goal
Research Beginner Protocol
Dose
20-30mcg · Once daily, post-workout
Route
Subcutaneous injection
Goal
Intermediate Research Use
Dose
40-60mcg · Once daily, post-workout or morning
Route
Subcutaneous or intramuscular
Goal
Advanced Research Protocol
Dose
80-100mcg · Once daily or split AM/PM
Route
Subcutaneous or site-specific IM
Goal
Women's Research Protocol
Dose
10-20mcg · Once daily
Route
Subcutaneous only
Research indications
muscle Growth
tissue Repair
metabolic
Administration
Interactions
Safety notes
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
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.