IGF-1 LR3
Also known as: Long R3 IGF-1, IGF-1 Long Arg3, LR3-IGF1
IGF-1 LR3 is a synthetic analog of insulin-like growth factor-1 with an extended half-life that promotes muscle growth, tissue repair, and cellular regeneration through enhanced IGF-1 receptor activation.
IGF-1 LR3 is a 9117.5 Da research peptide. IGF-1 LR3 is a synthetic analog of insulin-like growth factor-1 with an extended half-life that promotes muscle growth, tissue repair, and cellular regeneration through enhanced IGF-1 receptor activation.
Also called: Long R3 IGF-1, IGF-1 Long Arg3, LR3-IGF1
9117.5
Molecular Weight
Daltons
1
Strong Evidence
benefits
4
Studies Cited
peer-reviewed
20-40
Typical Dose
mcg
Overview
IGF-1 LR3 represents a modified version of human IGF-1 where the glutamic acid at position 3 has been replaced with arginine, and 13 amino acids have been added to the N-terminus. These modifications prevent binding to IGF binding proteins, resulting in a significantly longer half-life of 20-30 hours compared to natural IGF-1's 10-20 minutes. The peptide directly activates IGF-1 receptors throughout the body, triggering anabolic pathways that promote protein synthesis, muscle fiber development, and tissue regeneration. Research shows IGF-1 LR3 can increase muscle mass, accelerate recovery from exercise-induced damage, and enhance overall cellular growth processes. The extended half-life allows for less frequent dosing while maintaining consistent anabolic stimulation.
Key Takeaways: IGF-1 LR3
- Strongest evidence supports IGF-1 LR3 for muscle growth and hypertrophy
- Research doses typically range from 20 to 40 mcg via subcutaneous
- 1 benefits with strong evidence, 4 moderate, 2 preliminary
- Half-life: 20-30 hours
- 4 cited research studies in this guide
Mechanism of Action
IGF-1 LR3 binds to IGF-1 receptors on target cells, activating the PI3K/Akt signaling pathway. This leads to increased protein synthesis through mTOR activation, enhanced glucose uptake, and reduced protein degradation. The modified structure prevents binding to IGF binding proteins (IGFBPs), allowing for sustained receptor activation and prolonged anabolic effects throughout the body.
Research Benefits
IGF-1 LR3 at a Glance
IGF-1 LR3 binds to IGF-1 receptors on target cells, activating the PI3K/Akt signaling pathway.
Muscle Growth and Hypertrophy
Strong EvidenceStimulates satellite cell proliferation and myoblast differentiation, leading to increased muscle fiber size and number through enhanced protein synthesis rates.
Enhanced Recovery from Exercise
Moderate EvidenceAccelerates repair of exercise-induced muscle damage by promoting cellular regeneration and reducing inflammatory markers in skeletal muscle tissue.
Improved Nitrogen Retention
Moderate EvidenceShifts nitrogen balance toward positive retention by increasing amino acid uptake and reducing protein breakdown in muscle tissue.
Accelerated Wound Healing
Moderate EvidencePromotes fibroblast proliferation and collagen synthesis, leading to faster healing of cuts, scrapes, and tissue injuries.
Improved Glucose Metabolism
Moderate EvidenceEnhances insulin sensitivity and glucose uptake in muscle cells, potentially improving metabolic efficiency and energy utilization.
Enhanced Bone Density
PreliminaryStimulates osteoblast activity and bone formation while reducing osteoclast-mediated bone resorption, improving overall bone mineral density.
Neuroprotective Effects
PreliminarySupports neuronal survival and regeneration through activation of survival pathways in nervous tissue, potentially protecting against neurodegeneration.
Research Dosing Protocols
Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
| Research Protocol | Dose Range | Route |
|---|---|---|
| Muscle growth research | 20–40 mcg | subcutaneous |
| Recovery research | 30–60 mcg | subcutaneous |
| Tissue repair studies | 40–80 mcg | subcutaneous |
Frequency
Once daily or every other day
Timing
Post-workout or before bed
Cycle Length
4-6 weeks with 4-6 week breaks
Research Notes
- 1Start with lower doses to assess tolerance
- 2Rotate injection sites to prevent lipodystrophy
- 3Monitor blood glucose levels during research
- 4Consider splitting doses if using higher amounts
Reconstitution Guide
Standard Reconstitution
Vial Size
1 mg
Bacteriostatic Water
2 mL
Concentration
5 mcg
per 0.1 mL (10 units)
Step-by-Step Guide
Gather Materials
IGF-1 LR3 vial, bacteriostatic water, alcohol swabs, insulin syringes.
Equilibrate Temperature
Remove the vial from storage and allow it to reach room temperature (5-10 minutes).
Sanitize
Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.
Draw Water
Draw 2 mL of bacteriostatic water into a syringe.
Add Water to Vial
Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.
Mix Gently
Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.
Store Properly
Refrigerate at 2-8°C refrigerated. 4-6 weeks reconstituted.
Storage Temperature
2-8°C refrigerated
Shelf Life
4-6 weeks reconstituted
Important Notes
- •Use bacteriostatic water for reconstitution
- •Swirl gently to dissolve - do not shake vigorously
- •Store away from light and heat
- •Single-use vials should be used within 48 hours after first puncture
IGF-1 LR3 Dosing Calculator
Calculate daily intake, cycle totals, and vials needed with pre-filled protocols →
IGF-1 LR3 Reconstitution Calculator
Calculate concentration, syringe units, and doses per vial with auto-filled values →
Safety & Side Effects
Reported Side Effects
- !Hypoglycemia (low blood sugar)
- !Water retention and bloating
- !Joint pain and stiffness
- !Headaches and dizziness
- !Injection site reactions
- !Temporary insulin resistance
- !Organ enlargement (with chronic use)
- !Increased risk of tumor growth
- !Acromegaly-like symptoms
- !Carpal tunnel syndrome
Potential Interactions
- ⚡Insulin - increased risk of severe hypoglycemia
- ⚡Corticosteroids - may reduce IGF-1 effectiveness
- ⚡Growth hormone - potential additive effects
- ⚡Thyroid hormones - may alter IGF-1 metabolism
Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.
Research Studies
The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.
Effects of IGF-1 on skeletal muscle growth and repair
Demonstrated that IGF-1 overexpression in skeletal muscle leads to significant hypertrophy and enhanced regeneration following injury.
IGF-1 receptor signaling in muscle development
Comprehensive review of IGF-1 receptor activation pathways and their role in muscle protein synthesis and satellite cell activation.
Long R3 IGF-1 effects on protein synthesis
Study examining the enhanced anabolic effects of Long R3 IGF-1 compared to native IGF-1, showing prolonged stimulation of protein synthesis pathways.
IGF-1 and exercise-induced adaptations
Research on how IGF-1 mediates exercise-induced muscle adaptations and contributes to training responses.
Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.
Frequently Asked Questions
IGF-1 LR3 has arginine instead of glutamic acid at position 3 and 13 additional amino acids at the N-terminus. These modifications prevent binding to IGF binding proteins, extending the half-life from 10-20 minutes to 20-30 hours and allowing for sustained anabolic effects.
IGF-1 LR3 has a half-life of 20-30 hours, meaning it remains active much longer than natural IGF-1. This extended duration allows for less frequent dosing while maintaining consistent anabolic stimulation.
Research protocols typically use post-workout administration to take advantage of exercise-induced muscle sensitivity, or before bed to align with natural growth hormone release patterns during sleep.
Yes, IGF-1 LR3 can lower blood glucose levels by enhancing glucose uptake in muscle cells. Researchers should monitor blood sugar levels and have glucose readily available during studies.
Store reconstituted IGF-1 LR3 in the refrigerator at 2-8°C, protected from light. Use within 4-6 weeks of reconstitution and within 48 hours of first vial puncture for single-use preparations.
Subcutaneous injection into fatty tissue areas like the abdomen, thigh, or arm provides good absorption. Rotate injection sites to prevent tissue damage and lipodystrophy.
Research protocols typically use 4-6 week cycles followed by equal break periods to prevent receptor downregulation and allow natural IGF-1 production to normalize.
Chronic use of IGF-1 analogs can potentially cause unwanted tissue growth including organs. Research should be limited to appropriate durations with proper monitoring protocols.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.