Library · Muscle, bone & joint · Muscle growth and tissue repair enhancement
IGF-1 LR3
Long R3 IGF-1, IGF-1 Long Arg3, Recombinant Human IGF-1 Long R3
Synthetic IGF-1 analog engineered for longer half-life and reduced binding to IGF-binding proteins, making it far more potent than natural IGF-1. Used in research on cell growth and differentiation, but widely misused in bodybuilding for muscle building.
Research score 40/100. Reference only, not a dose.
- Muscle Growth
- Recovery Enhancement
- Angiogenesis
- Growth Hormone Release
- Healing
- US status
- Research Chemical
- Approval
- Research Chemical Only
- Evidence
- No FDA approval. Limited human clinical data (mostly anecdotal/gray market).
- Research score
- 40 / 100
- Indication
- Research Only - No Medical Indication
- Origin
- Australia
- Source category
- Muscles & Joints
- Status group
- Research chemical
Mechanism
An arginine substitution and 13-amino-acid N-terminal extension cut IGF-binding-protein attachment and extend circulation time; acting through the IGF-1 receptor, it strongly drives PI3K/Akt/mTOR and MAPK/ERK signaling, boosting protein synthesis, amino acid uptake, and satellite-cell activity in muscle.
Safety file
High risk of hypoglycemia; potential for organ enlargement (acromegaly), insulin resistance, and cancer promotion. Not approved for human therapeutic use.
- Hypoglycemia
- Joint pain
- Water retention
- Possible growth of existing tissues including unwanted growth
- Headaches