Peptide Research Index
⚠️ Educational only · Not medical advice · Consult a doctor · Most peptides are research-only / not FDA-approved for human use
⚠️ Educational only · Not medical advice · Consult a doctor · Most peptides are research-only / not FDA-approved for human use
Also: Insulin-like Growth Factor 1 Long R3
Growth FactorLast Updated: April 1, 2026
IGF-1 LR3 (also known as Insulin-like Growth Factor 1 Long R3) is a prominently researched experimental compound classified strictly within the Growth Factor framework. Operating primarily through advanced pharmacological pathways, it functions by iGF-1 analog with extended half-life for muscle cell hyperplasia (new cell creation, not just hypertrophy). Promotes nitrogen retention and protein synthesis. with a documented biological half-life of roughly 20 hours, in preclinical investigative trials and independent academic studies, researchers utilizing IGF-1 LR3 have documented significant, quantifiable biological outcomes, primarily focusing on muscle growth, recovery, hyperplasia. Typical research protocols investigate administering 50 to 50mcg via subq pathways 5x/wk. However, it is critically important to understand that while IGF-1 LR3 demonstrates profound physiological potential in highly controlled laboratory settings, it remains classified strictly as a research chemical and has not been approved by the United States Food and Drug Administration (FDA) for human therapeutic, diagnostic, or dietary consumption. Independent chemical analysis via rigorous third-party Certificate of Analysis (COA) testing utilizing High-Performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS) remains the industry gold standard for verifying its base elemental stability when reconstituted appropriately in sterile bacteriostatic water.
IGF-1 analog with extended half-life for muscle cell hyperplasia (new cell creation, not just hypertrophy). Promotes nitrogen retention and protein synthesis.
IGF-1 LR3 demonstrates significantly enhanced potency over native IGF-1 due to reduced binding protein affinity and extended half-life, promoting dose-dependent muscle growth.
preclinicalPhilippou & Barton (Growth Hormone & IGF Res.): Comprehensive review of IGF-1's role in muscle satellite cell activation, myoblast proliferation, and skeletal muscle regeneration.
preclinicalBowers et al.: Meta-analysis of epidemiological studies examining positive correlation between circulating IGF-1 levels and prostate, breast, and colorectal cancer risk.
moderate strongPotent; use caution. Risk of hypoglycemia. Theoretical cancer promotion concern well-documented in literature. Research-only.
⚠️ For educational purposes only. Not medical advice. Consult a healthcare professional before using any peptide.
Very low doses. Inject post-workout for localized muscle effects. Monitor blood sugar closely. Short cycles only.
Last updated: 2026-01 · Laws change frequently. Verify current status in your jurisdiction.
Week 1
Enhanced nutrient partitioning; increased post-workout pumps
Weeks 2-4
Lean mass and recovery improvements; possible hypoglycemia if undereating
Month 2-3
Significant body composition changes; hyperplasia (new cell creation) possible
Long-term
Theoretical cancer promotion risk with chronic use; short cycles essential
| Side Effect | Incidence | Severity |
|---|---|---|
Hypoglycemia Especially if dosed without food nearby; have glucose on hand | ~10% of users | moderate |
Joint pain | ~8% of users | mild |
Headache | ~5% of users | mild |
Fluid retention | ~10% of users | mild |
Incidence rates sourced from published clinical trial data where available; otherwise based on community research observations.
Finding verified, high-purity IGF-1 LR3 requires rigorous COA verification. We independently evaluate vendors based on third-party HPLC testing, purity thresholds (≥98%), and batch-specific documentation.
View COA-Verified IGF-1 LR3✓ Third-party tested·✓ US shipping·✓ COA on every batch
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Maximize absolute lean muscle gain through sustained GH optimization and direct muscle cell hyperplasia
PeptiDex. (2026). IGF-1 LR3. PeptiDex Research Platform. https://peptidex.app/library/igf-1-lr3
12 stacks • exact dosages • cycle lengths • printable reference
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