What is IGF-1 LR3?
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a recombinant analog of IGF-1 with an Arg3 substitution and a 13-amino acid N-terminal extension. These modifications dramatically reduce binding to IGF-binding proteins (IGFBPs), resulting in a ~20–30 hour half-life (vs. 12–15 hours for native IGF-1) and significantly greater tissue exposure and anabolic potency. Research only; not FDA-approved.
Mechanism of Action
Full IGF-1 receptor (IGF1R) agonism; reduced IGFBP binding increases free bioavailable fraction; activates PI3K/Akt/mTOR for protein synthesis and cell proliferation; promotes glucose uptake and satellite cell activation
Target: IGF-1 receptor (IGF1R), PI3K/Akt/mTOR pathway
Research Indications
Stimulates natural GH release through pituitary signaling pathways
Associated with increased lean mass and reduced body fat
Supports tissue repair and recovery from exercise or injury
Some protocols show improvements in slow-wave and restorative sleep
Research Protocols
These are commonly discussed research protocols — not medical advice. Consult a healthcare provider before use.
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Conservative Start (Week 1-2) | 20 mcg | Once daily | Subcutaneous injection |
| Standard Body Comp Range | 40-80 mcg | Once daily | Subcutaneous injection |
| Advanced Short Cycle | 80-120 mcg | Once daily | Subcutaneous injection |
Peptide & Drug Interactions
Always consult your healthcare provider before combining with other compounds. Use our Interaction Checker for reference.
How to Reconstitute & Inject
Use bacteriostatic (BAC) water only. Avoid saline — may cause precipitation. Refrigerate and use within 28 days.
- 1
Remove IGF-1 LR3 vial from refrigeration and allow to reach room temperature (15–20 minutes)
- 2
Clean vial top with alcohol swab and allow to air dry completely
- 3
Using a sterile syringe, draw the calculated volume of bacteriostatic water (BAC water)
- 4
Inject BAC water slowly down the side of the vial — do not aim directly at the powder
- 5
Gently swirl in circular motions — DO NOT shake vigorously as this degrades the peptide
- 6
Allow 2–3 minutes for full dissolution — solution should be clear and colorless
- 7
Draw calculated dose into an insulin syringe for subcutaneous injection
- 8
Inject into abdomen, thigh, or upper arm. Rotate injection sites to prevent lipodystrophy
- 9
Store reconstituted solution refrigerated (2–8°C) and use within 28 days
What to Expect
Week 1–2
Improved sleep quality may begin. Mild water retention possible initially.
Week 2–4
Deeper sleep, improved recovery. Appetite may increase slightly.
Week 4–8
Noticeable improvements in body composition, energy, and recovery speed.
Week 8–12
Skin quality improvements, reduced body fat, increased lean mass becoming visible.
Week 12+
Sustained improvements in body composition, strength, and overall vitality.
Side Effects & Safety
- Water retention and mild bloating, especially early in protocol
- Increased appetite (particularly with GHRP compounds)
- Flushing or warmth at injection site
- Tingling or numbness (carpal tunnel-like symptoms at higher doses)
- Fatigue or lethargy if dosed at suboptimal times
- Cortisol and prolactin elevation possible (especially GHRP-6)
- Rare: Elevated blood glucose — monitor if diabetic or pre-diabetic
FDA Status & Regulatory Info
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a recombinant analog of IGF-1 with an Arg3 substitution and a 13-amino acid N-terminal extension. These modifications dramatically reduce binding to IGF-binding proteins (IGFBPs), resulting in a ~20–30 hour half-life (vs. 12–15 hours for native IGF-1) and significantly greater tissue exposure and anabolic potency. Research only; not FDA-approved.
Frequently Asked Questions
Research References
External links for education only. We do not control third-party content.
Community-reported data
The information below reflects self-reported experiences from PeptIQ app users. It is not clinical evidence and should not replace professional medical advice.
Community Intelligence
What 30 users report
Positive 97% · Neutral 3% · Negative 0%
Most reported benefits
Most reported side effects
Dose distribution
Median: 50–100 mcg · Most common: 0–25 mcg
Commonly stacked with
How repeat users are trending
Among repeat reporters, 96% said they felt similar to their last entry, 4% more positive, and 0% more negative.
Overall, repeat reporters leaned more positive than their previous entry.
Median gap between entries: 153 days · Based on 28 repeat reporters
Share Your Experience
Rate IGF-1 LR3 in the PeptIQ app and help the community make informed decisions.
Research purposes only
This page is for educational reference. It is not medical or legal advice. Consult the FDA and a licensed healthcare professional for current regulations and individualized guidance.