IGF-LR3
A modified IGF-1 with extended half-life that directly stimulates muscle cell growth and differentiation.
Medically reviewed by Dr. Jonathan Snipes, MD. Last reviewed May 6, 2026.What It Is
IGF-LR3 is a modified version of Insulin-like Growth Factor 1 with a longer active life. It works directly at the muscle cell level to promote growth.
How It Works
Unlike GH secretagogues that work upstream, IGF-LR3 binds directly to IGF-1 receptors on muscle cells, promoting hyperplasia (new cell growth) and hypertrophy (cell enlargement).
Who It's For
Advanced users seeking direct muscle growth support. Often used by athletes in recovery phases or those wanting to maximize lean tissue development.
Who Should Avoid It
Not for those with active cancer or diabetes. Requires careful blood sugar monitoring. Provider supervision essential.
Protocol & Pricing
OBP Pharmacy Price
$145/1mg
You pay pharmacy price. No markup.
Starting Dose
20-40mcg/day
Form
Injectable vial (5mL, 200mcg/mL, 1mg total)
Dosing Protocol
20-40mcg subcutaneous injection daily. Use for 4-6 week cycles. Monitor blood sugar.
Beyond Use Date
180 Days from compounding (USP <797>)
Use within this window from the date your vial is compounded. BUD is set per USP <797> sterile compounding standards and printed on every label.
Stacking Guide
Stacks Well With
Related Peptides
Common questions about IGF-LR3
- What is IGF-1 LR3?
- IGF-1 LR3 is a modified version of insulin-like growth factor 1 (IGF-1) with an extended half-life (~20 to 30 hours versus 10 to 20 minutes for native IGF-1) achieved by an arginine-leucine substitution at position 3 and a 13-amino acid extension at the N-terminus. The longer half-life makes it practical to dose subcutaneously once daily rather than by continuous infusion. IGF-1 mediates the anabolic effects of growth hormone on muscle, bone, and tendon.
- Does IGF-1 LR3 build muscle?
- IGF-1 LR3 increases protein synthesis and muscle satellite-cell activation in animal studies. In bodybuilding and athletic-performance contexts it is used at doses ranging from 20 to 100 mcg per day for 4 to 6 week cycles. Effects are most pronounced when paired with sufficient training stimulus and protein intake. Long-term continuous use is not recommended because IGF-1 LR3 can drive cell proliferation in tissues beyond muscle.
- How is IGF-1 LR3 dosed?
- Common protocols deliver 20 to 50 mcg per day for sport/athletic protocols, dosed subcutaneously once daily either in the morning or post-training. Optimal Balance Pharmacy compounds IGF-1 LR3 against PeptideRx prescriptions; the per-dose draw on your insulin syringe depends on the vial concentration printed on your label. Cycle 4 to 6 weeks on, then 4 weeks off.
- Where and when do I inject IGF-1 LR3?
- Subcutaneous injection into the abdomen, upper outer thigh, or back of the upper arm using a 31-gauge, 5/16-inch (8 mm) needle on a U-100 insulin syringe. Some athletes inject directly subcutaneously over the muscle group they trained that day; the localized effect is debated but the systemic effect from any subcutaneous site is the same.
- How is IGF-1 LR3 supplied?
- Compounded by Optimal Balance Pharmacy under a 503A patient-specific prescription. Ships pre-reconstituted and ready to inject in cold-chain packaging. Every batch is tested by Eagle Analytical Services; the Certificate of Analysis is published on this product page. Refrigerate per the printed label; do not freeze.