IGF-1
About
About IGF-1
Insulin-like growth factor 1 (IGF-1) is the primary mediator of GH anabolic effects and is produced mainly in the liver. Recombinant IGF-1 (mecasermin) is FDA-approved for severe primary IGF-1 deficiency. In optimization medicine, lr3-IGF-1 (a longer-acting analog) is used off-label for muscle growth, recovery, and neuroprotection. It is a potent anabolic compound requiring careful titration.
Science
Mechanism of Action
Binds IGF-1 receptors on muscle, bone, and neural tissue, activating PI3K/Akt/mTOR signaling pathways to promote protein synthesis, cell survival, glucose uptake, and neural plasticity.
Dosing
Typical Protocol
20–80 mcg subcutaneous injection once daily post-workout; lr3-IGF-1 used at 20–100 mcg with longer activity window.
⚠ Protocol information is for educational purposes only. Dosing must be determined by a licensed physician based on individual health status and goals.
Regulatory
Legal Status in 2026
This compound occupies a regulatory grey area in 2026. It is neither explicitly FDA-approved nor clearly illegal for personal use, but it lacks formal clinical approval and may not be legally sold for human use in all contexts. Proceed with caution: source quality is variable, and regulatory status can change. Always consult a physician.
Evidence
Evidence Tier
Evidence from randomized controlled trials (RCTs) or large observational studies in humans. This is the gold standard — effects have been measured in controlled conditions and results are peer-reviewed and reproducible.
Find a Verified Provider
See which Vial-verified providers offer IGF-1 — with trust scores, legal credentials, and pricing transparency.