IGF-1 LR3 Protocol Guide
IGF-1 LR3 (Long R3 Insulin-Like Growth Factor-1) is a modified analog of IGF-1 with 83 amino acids. The glutamic acid at position 3 is replaced with arginine, and a 13-amino acid extension peptide is added to the N-terminus. These modifications dramatically reduce binding to IGF binding proteins (IGFBPs), extending the half-life from ~15 minutes (native IGF-1) to 20-30 hours and increasing free bioactive IGF-1 signaling. It promotes muscle cell hyperplasia (new cell formation, not just hypertrophy), enhances protein synthesis, increases glucose uptake, and supports recovery. This protocol covers 20-60mcg daily dosing for 4-6 week cycles with mandatory glucose monitoring.
Protocol Overview
- Compound
- IGF-1 LR3 (Long R3 IGF-1)
- Category
- Modified Growth Factor / Anabolic Peptide
- Mechanism
- IGF-1 receptor agonist with reduced IGFBP binding; activates PI3K/Akt/mTOR pathway; promotes muscle hyperplasia + hypertrophy; enhances glucose uptake; anti-apoptotic signaling
- MW
- ~9,111 Da (83 amino acids)
- Half-Life
- 20-30 hours (vs ~15 min native IGF-1)
- Vial
- 100mcg or 1mg lyophilized
- Route
- Subcutaneous or intramuscular
- Frequency
- Daily (post-workout preferred)
- Cycle
- 4-6 weeks on / 4 weeks off
Dosing
| Protocol | Dose | Frequency | Notes |
|---|---|---|---|
| Conservative | 20-30 mcg/day | Daily, post-workout | Start here; assess glucose response |
| Standard | 40-50 mcg/day | Daily, post-workout | Most common research dose |
| Advanced | 50-80 mcg/day | Daily, post-workout | Higher risk; experienced users only |
Reconstitute with bacteriostatic water or 0.6% acetic acid. IGF-1 LR3 is fragile — do not shake, store at 2-8C. Inject post-workout for maximum nutrient partitioning. Subcutaneous (bilateral abdomen) for systemic effects or intramuscular into target muscle group. Always have fast-acting carbs available for hypoglycemia management.
Timeline
Side Effects & Stacking
Side Effects
- Hypoglycemia (most critical — monitor glucose closely)
- Gut distension at high doses or long cycles
- Joint pain / water retention
- Organ growth risk with prolonged use
- Potential tumor promotion (IGF-1 is proliferative — avoid with cancer history)
- Lethargy and fatigue (glucose-related)
- Numbness/tingling in extremities
Stacking
- HGH (Somatropin): Synergistic GH+IGF-1 axis (classic combination)
- BPC-157 + TB-500: Recovery and injury repair amplification
- MK-677: Endogenous GH support (alternate to exogenous HGH)
- Testosterone/TRT: Complementary anabolic pathways
- Do NOT combine with: Insulin (extreme hypoglycemia risk)
Blood Work
| Panel | Markers | Timing |
|---|---|---|
| GH/IGF Axis | IGF-1, IGFBP-3 | Baseline, Week 4 |
| Glucose | Fasting glucose, HbA1c, fasting insulin, HOMA-IR | Baseline, Week 2, Week 4 |
| Organ Function | CMP (liver + kidney), CBC | Baseline, Week 4 |
| Lipids | Full lipid panel | Baseline, Week 4 |
| Tumor Markers | PSA (males), CEA (if applicable) | Baseline |
Critical: Monitor blood glucose daily during the first week. Keep fast-acting carbohydrates accessible at all times. If fasting glucose drops below 70 mg/dL, reduce dose or discontinue. IGF-1 LR3 is contraindicated in individuals with any history of cancer due to its proliferative signaling.
