meto
Peptide

IGF-1 LR3

Also known as Long R3 IGF-1

A modified, long-acting variant of IGF-1 with reduced binding-protein affinity — potent but with a serious safety profile for most use-cases.

Definition

IGF-1 LR3 is a synthetic IGF-1 analog with an arginine substitution and a 13-amino-acid N-terminal extension that reduces binding to IGF-binding proteins, dramatically extending its half-life and free-activity fraction. It's potent, with a much greater hypoglycaemic and tumour-promotion concern profile than upstream GH-axis peptides. Not used in mainstream clinical peptide medicine.

How Meto uses it.

Not part of Meto's catalogue. The safety profile — including significant hypoglycaemia risk and theoretical tumour-promoting activity — makes upstream GH-axis peptides (Sermorelin, Tesamorelin) the preferred clinical route.

Safety notes

  • Significant hypoglycaemia risk
  • Theoretical tumour-promotion concern from sustained high free-IGF-1 activity
  • Prohibited under WADA rules
  • Not recommended outside specialised research contexts

Not a complete list — your clinician reviews your full history, labs and medications during intake. Nothing here replaces that.

$149 panel.
A clinician reads it in 24 hours.

Order the Peptide Readiness Panel, draw at a Quest or LabCorp near you, and your clinician sends back a matched protocol with a confidence score.