IGF-1 LR3
Long-acting form of IGF-1 that stimulates new muscle cell growth
Direct IGF-1 receptor activation.
Hypoglycemia riskA modified form of IGF-1 with a 3-amino-acid extension and an Arg substitution — makes it ~3× more potent and much longer-acting than native IGF-1.
- Bypasses IGF-binding proteins, giving 20–30× greater free bioavailability.
- Half-life ~20–30 hours vs. ~20 minutes for native IGF-1.
- Activates mTOR, driving protein synthesis and cell proliferation.
IGF-1 LR3 is a modified, longer-lasting version of Insulin-like Growth Factor 1 — the hormone responsible for most tissue growth downstream of growth hormone. Unlike standard muscle growth (which enlarges existing cells), IGF-1 can trigger hyperplasia — the creation of new muscle cells. It's an advanced compound with significant risks.
How long it stays, how it leaves.
Fixed dosing — not weight-adjusted. The calculator handles reconstitution math for common vial sizes so you inject the right volume every time.
Three tiers, three goals.
Inject into the muscle you just trained
What people actually report.
- Low blood sugar (can be dangerous)
- Joint pain
- Jaw/hand growth at high doses
- Organ growth with long-term use
Before you start.
- Serious risk of low blood sugar — always have candy/juice nearby
- Doesn't use your body's safety limits — can cause excess growth
- Must cycle on and off — don't run continuously
- Not recommended without doctor supervision
- Monitor blood sugar closely
Combinations worth knowing.
Full Growth Stack
GH secretagogues raise your natural growth hormone while IGF-1 LR3 adds direct muscle cell stimulation. For advanced users only.