All Peptides›Articles›IGF-1 LR3 Dosage: 20-50mcg/Day Chart + Calculator
guidesApril 25, 2026·6 min read
IM hits one muscle, SubQ goes systemic — the route changes everything. 10-on/4-off protocol, bilateral splits, and reconstitution math.
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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
Parameter Detail Dose 50 mcg per injection Route Subcutaneous or intramuscular Timing AM Frequency 10 days in a row Cycle 10 days on, 4 weeks off Vial size 1 mg Reconstitution 1 mL BAC water (1,000 mcg/mL) Community-documented draw 5 units on insulin syringe Storage Refrigerate, use within 28 days
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.
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
Vial Size BAC Water Concentration 50 mcg Dose 1 mg 1 mL 1,000 mcg/mL 5 units
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.
Top IGF-1 LR3 Vendors
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Affiliate disclosure: vendor links in this article are affiliate links — The Peptide Catalog may earn a commission if you buy through them, at no additional cost to you.
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
Stack IGF-1 LR3 Dose Partner Partner Dose Purpose MK-677 20-40 mcg post-workout MK-677 12.5-25 mg PM Growth stack BPC-157 20-40 mcg post-workout BPC-157 250-500 mcg Growth + recovery CJC-1295/Ipamorelin 20-30 mcg post-workout CJC/Ipa Per protocol Comprehensive GH/IGF-1 axis
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.
Dose (mcg) Volume (mL) Units (insulin syringe) 25 mcg 0.025 mL 2.5 units 50 mcg 0.05 mL 5 units 75 mcg 0.075 mL 7.5 units 100 mcg 0.1 mL 10 units
Reconstitution B: 1 mg vial + 3 mL BAC water (333 mcg/mL) — more BAC water for larger, easier-to-measure draws.
Dose (mcg) Volume (mL) Units (insulin syringe) 25 mcg 0.075 mL 7.5 units 50 mcg 0.15 mL 15 units 75 mcg 0.225 mL 22.5 units 100 mcg 0.3 mL 30 units
These conversions reflect the dilutions documented in community reconstitution protocols. They report how the math is described, not a recommended dosing schedule.
Core Supplies for This Protocol
The three essentials for running any reconstituted injectable: cold storage, accurate syringes, and metabolic tracking.
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Frequently Asked Questions What is the standard IGF-1 LR3 dose?
The standard documented protocol is 50 mcg subcutaneously or intramuscularly once daily in the morning, for 10 consecutive days followed by 4 weeks off. Protocols describe drawing 5 units from a 1 mg vial reconstituted with 1 mL BAC water. What is the difference between IGF-1 and IGF-1 LR3?
IGF-1 LR3 is a modified analog with an arginine substitution at position 3 and 13 additional amino acids at the N-terminus. This reduces binding to IGF binding proteins, extending its half-life from minutes to 20-30 hours and increasing potency. What routes of administration are documented for IGF-1 LR3?
Both routes are used. Subcutaneous provides systemic distribution; intramuscular (into trained muscles post-workout) is theorized to provide more localized growth stimulus, though site-specific enhancement is debated. What cycle length do documented protocols describe for IGF-1 LR3?
The standard protocol is 10 days on, then 4 weeks off. Community sources attribute this pattern to preventing IGF-1 receptor desensitization and managing potential side effects from prolonged elevated IGF-1 activity. What are the risks of IGF-1 LR3?
Key risks include hypoglycemia, potential organ growth with chronic use, theoretical cancer risk from prolonged growth factor elevation, and joint/connective tissue changes. Community sources and research documentation consistently describe IGF-1 LR3 as among the higher-risk research peptides, citing hypoglycemia, organ growth potential, and long-term IGF-1 elevation concerns. Can IGF-1 LR3 be stacked with growth hormone?
Yes, but this is an advanced protocol with increased risk. GH naturally raises IGF-1, so adding exogenous IGF-1 LR3 creates supraphysiological levels. Community stacking protocols describe starting at lower IGF-1 LR3 doses (20 mcg) when combining with GH due to the additive effect on serum IGF-1.
IGF-1 LR3 Benefits: 5 Effects Ranked — evidence-ranked benefits with cited studies IGF-1 LR3 peptide page — vendor pricing and full profile Follistatin Benefits Guide — myostatin inhibitor often stacked with IGF-1 pathways MK-677 Dosing Guide — oral GH secretagogue for stacking Ipamorelin Dosing Guide — GH secretagogue with clean release profile BPC-157 Dosing Guide — recovery peptide to complement anabolic protocols Peptide Stacking Guide — principles for combining growth peptides Calculate Your IGF-1 LR3 Cycle Cost — estimate vials needed and total cost Best Peptides for Muscle Growth (2026) — all 10 muscle-building peptides ranked
References
Citation Topic PMID Adams & McCue, Journal of Applied Physiology (1998) IGF-1 satellite cell activation and muscle hypertrophy 10632630 Bastian et al., Journal of Endocrinology (1993) LR3 IGF-1 organ growth, IGFBP suppression 7561636 Florini et al., Endocrine Reviews (1996) IGF-1 in muscle metabolism and myogenesis 11493020
For educational and research purposes only. This is not medical advice. IGF-1 LR3 is a research compound with no FDA approval. It carries significant risks including hypoglycemia and theoretical cancer concerns.