IGF-1 LR3
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a modified version of IGF-1 with extended half-life and enhanced potency. The modifications prevent binding to IGF binding proteins, increasing bioavailability.
Mechanism of Action
Binds to IGF-1 receptors to promote protein synthesis, muscle growth, and fat metabolism. The LR3 modification (13 amino acid extension and arginine substitution) extends half-life from minutes to 20-30 hours.
Dosage Overview
Dose Range
20 mcg – 100 mcg
Route
subcutaneous
Frequency
1x daily
Cycle Length
4–6 weeks
Reconstitution
Typical Dosage (Research)
Research protocols typically use 20-100mcg daily, often divided into multiple injections or administered bilaterally to target muscles.
Intramuscular injection (site-specific growth) or subcutaneous for systemic effects. Often cycled 4-6 weeks on, equal time off.
Considerations for Men & Women
Women: IGF-1 levels are influenced by estrogen status — premenopausal women naturally have different IGF-1 dynamics than postmenopausal women. Potent growth factor; contraindicated during pregnancy. May affect menstrual regularity at higher doses.
Men: Often used in muscle growth research. Testosterone can synergize with IGF-1 signaling. Hypoglycemia risk exists for both sexes — always use with food. Monitor for joint pain and edema.
Individual responses vary. These notes reflect general trends from research literature and are not medical advice.
Quick Calculator
Quick Calculator
Concentration: 1,000 mcg/ml
Volume to inject: 0.02 ml
Syringe units (U-100): 2.0 units
Pre-filled with IGF-1 LR3 defaults. Adjust values as needed.
Side Effects & Risks
Hypoglycemia, joint pain, water retention, potential jaw/hand growth with extended use, and injection site reactions.
May promote growth of existing tumors. Can cause significant hypoglycemia. Long-term effects on insulin sensitivity concerning.
Where to Buy IGF-1 LR3
All Vendor Details →US-based vendor with third-party HPLC testing and published COAs. One of the few reputable sources we've verified for research-grade peptides.
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Finnrick grades are based on independent HPLC lab testing. Learn more · Finnrick is a commercial service — ratings are third-party, not independent.
Who Uses IGF-1 LR3
Bodybuilders seeking muscle growth, those in aggressive recovery protocols.
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