IGF-1 LR3 Dosage: 20-50mcg/Day Chart + Calculator

IGF-1 LR3 is a modified analog of IGF-1 with a dramatically extended half-life (20-30 hours vs minutes) and enhanced potency. It drives muscle growth through satellite cell activation and protein synthesis — mechanisms documented in human and animal models (Adams & McCue, 1998) — but carries meaningful risks including hypoglycemia. For a full breakdown of what this peptide does, see our IGF-1 LR3 benefits guide. This is not medical advice.

Research-context information only. IGF-1 LR3 is a research peptide. Protocols, doses, and reactions reported below come from published research and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.

Quick Reference: Standard Protocol

Draw volumes reflect community-documented reconstitution protocols, not a recommended dosing schedule.

For GH secretagogue comparisons, see our MK-677 dosing guide and Ipamorelin dosing guide.

Cycling Details

The standard protocol is 10 consecutive days of daily injections, followed by 4 weeks off. This short, aggressive cycle is designed to maximize anabolic stimulus while minimizing risks from prolonged IGF-1 elevation.

Community protocols describe keeping fast-acting carbohydrates available — hypoglycemia is the most immediate risk. Community sources warn against injecting before sleep. Documented protocols describe starting at 20 mcg for the first 2-3 days to assess tolerance, then increasing to 50 mcg if well-tolerated.

Enhanced Protocol (Community)

Some advanced users run longer cycles or higher doses:

• 4-6 week cycle: 20-50 mcg daily, 4-6 weeks off (less common, higher risk)
• Bilateral IM split: 40-80 mcg/day split between muscle groups post-workout
• Training-day only: 50 mcg on training days (4-5x/week) for 4 weeks

The standard 10-day on / 4-week off protocol is the most commonly documented starting point in community sources.

Routes of Administration

Subcutaneous: Abdomen or love handles. Provides systemic IGF-1 LR3 distribution. Consistent absorption, easier injection.

Intramuscular: Biceps, deltoids, quads — inject into muscles trained that day. Preferred in bodybuilding communities for theoretical local growth enhancement, though site-specific effects are debated.

Reconstitution Quick Reference

Math: 1,000 mcg / 1 mL = 1,000 mcg/mL. 50 mcg / 1,000 = 0.05 mL = 5 units. Swirl gently — IGF-1 LR3 is fragile. Some protocols use 0.6% acetic acid instead of BAC water for improved stability. Refrigerate, use within 28 days.

For step-by-step reconstitution instructions, see the BPC-157 reconstitution guide — same general technique applies.

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Where These Numbers Come From

IGF-1 LR3 is a research tool and performance compound — it does not have human clinical trial data for the way it's used in the community.

IGF-1 induces muscle hypertrophy through satellite cell activation and increased protein synthesis in differentiated myofibers (Adams & McCue, 1998). LR3 IGF-1 infusion in animal models stimulates organ growth (adrenals, gut, kidneys, spleen) while suppressing endogenous IGF-1 and IGFBP levels (Bastian et al., 1993).

The LR3 modification provides a 20-30 hour half-life (vs minutes for native IGF-1), reduced IGFBP binding, and approximately 2-3x potency. Community doses of 20-80 mcg daily are extrapolated from animal research scaling, decades of bodybuilding experience, potency considerations, and risk management balancing anabolic effects against hypoglycemia (Florini et al., 1996).

Stacking Protocols

Community protocols describe running IGF-1 LR3 alone first and lowering LR3 doses to 20-30 mcg when stacking. Community sources emphasize watching blood sugar closely, since multiple compounds may compound hypoglycemia risk, and describe blood work (IGF-1, glucose, insulin, HbA1c) as essential.

Side Effects & Safety

• Hypoglycemia (most immediate risk) — shaking, dizziness, sweating, confusion; community sources describe keeping fast-acting carbs available
• Organ growth — gut distension and cardiomegaly possible with prolonged, high-dose use
• Jaw and hand growth — subtle acromegaly-like changes with chronic use
• Cancer risk — chronically elevated IGF-1 is associated with increased cancer risk in epidemiological studies
• Joint pain — connective tissue changes, water retention
• Fatigue/lethargy — common, especially initially
• Injecting before sleep — community sources warn against this, as hypoglycemia during sleep is dangerous

mg to Units Conversion

On a standard 100-unit insulin syringe, each "unit" equals 0.01 mL (so 100 units = 1 mL). Once IGF-1 LR3 is reconstituted, the conversion from a target dose to syringe units depends on the chosen dilution.

The two reconstitution ratios most often described in community protocols are below.

Reconstitution A: 1 mg vial + 1 mL BAC water (1 mg/mL) — the standard dilution from the Quick Reference above.

Reconstitution B: 1 mg vial + 3 mL BAC water (333 mcg/mL) — more BAC water for larger, easier-to-measure draws.

These conversions reflect the dilutions documented in community reconstitution protocols. They report how the math is described, not a recommended dosing schedule.