IGF-1 LR3
Insulin-like Growth Factor-1 Long Arg3 · Long-chain IGF-1 variant
A modified analogue of Insulin-like Growth Factor 1 with an arginine substitution at position 3 and a 13-amino-acid extension at the N-terminus. The modifications dramatically extend its half-life and reduce binding to IGF-binding proteins, making it useful for studying IGF-1 receptor signalling in isolation.
What IGF-1 LR3 does — and how it works
IGF-1 LR3 is a synthetic long-acting analogue of endogenous IGF-1. The “LR3” designation refers to the Long Arg3 modification: an arginine substitution at amino acid position 3, combined with a 13-amino-acid N-terminal extension. Together these changes reduce binding to IGF-binding proteins (IGFBPs) by approximately 1000-fold, dramatically extending active half-life from minutes to hours.
This extended activity window makes IGF-1 LR3 a useful research tool for studying IGF-1 receptor-mediated signalling in muscle tissue, cellular proliferation, and satellite cell activation without the rapid clearance that limits studies using native IGF-1.
What researchers study it for
| Area | What studies look at | Evidence |
|---|---|---|
| Muscle hypertrophy | Satellite cell activation; myoblast proliferation and differentiation in muscle injury models | Animal |
| IGF-1 receptor signalling | PI3K/Akt/mTOR pathway activation; downstream anabolic signalling cascades | In vitro + animal |
| Nitrogen retention | Protein synthesis upregulation; anti-catabolic effects in fasting models | Animal |
| Fat metabolism | Glucose uptake in muscle vs adipose tissue; fat oxidation in GH-deficient models | Animal |
| Neuroprotection | Neurite outgrowth; nerve injury recovery; IGF-1R expression in CNS tissue | Preliminary |
Most IGF-1 LR3 research is conducted in vitro or in animal models. There is very limited human clinical data for this specific analogue.
How it works
How to reconstitute IGF-1 LR3
IGF-1 LR3 comes as a lyophilized (freeze-dried) powder. It is typically supplied in 1mg vials. Add 1mL of BAC water for a clean 1mg/mL working concentration — small volumes make precise dosing easier at the low mcg ranges used in research.
Step-by-step
- Gather supplies: IGF-1 LR3 vial, BAC water, insulin syringe (28–31 gauge), alcohol swabs.
- Swab both vial tops with separate swabs. Let air dry 10–15 seconds.
- Draw the BAC water into the syringe.
- Inject slowly down the glass wall — don’t hit the powder directly. IGF-1 LR3 can be fragile under physical stress.
- Swirl gently until fully dissolved. Do not shake. Solution should be clear.
- Label with date and refrigerate immediately at 2–8°C. Use within 14 days.
Common research frameworks
IGF-1 LR3 is dosed at low mcg amounts — far smaller than most injectable peptides. No titration is needed, but careful measurement is essential given the low volumes involved.
| Schedule | Daily dose | Frequency | Notes |
|---|---|---|---|
| Standard | 20–60mcg | Once daily | Most commonly referenced range. Often timed post-workout in muscle research. |
| Low-dose | 10–20mcg | Once daily | Extended protocols. Reduced hypoglycaemia risk at this range. |
All figures are derived from research literature. Not clinical recommendations. IGF-1 LR3 has significant hypoglycaemic potential — glucose monitoring is a standard safety precaution in research settings.
Storage requirements
Lyophilized (dry)
Lyophilized (dry)
Reconstituted
Reconstituted
What you’ll need
| Item | Spec | Notes | Source |
|---|---|---|---|
| Bacteriostatic water | 10mL multi-dose vial | Required for reconstitution. | ManaWell → |
| Insulin syringes | 28–31 gauge, 0.5mL or 1mL | Used for both reconstitution and administration. | Amazon → |
| Alcohol swabs | 70% isopropyl | For swabbing vial tops before each draw. | Amazon → |
| Sharps container | 1-quart, FDA-approved | For proper needle disposal. | Amazon → |
IGF-1 LR3 suppliers
| Supplier | Size | Price | Coupon | |
|---|---|---|---|---|
Amino Club ● In stock | 1mg vial | $69.99 | PEPTIDEREF | Shop → |
Prices verified March 2026. Affiliate links — we may earn a commission. Always verify current pricing on supplier sites.
All content on PeptideRef.co is for informational and research purposes only. Nothing on this page constitutes medical advice. IGF-1 LR3 is intended for laboratory research use only and is not approved for human or veterinary consumption. PeptideRef may earn affiliate commissions from qualifying purchases.