| Compound | IGF-1 LR3 |
|---|---|
| Category | Long-acting IGF-1 analog |
| Class | Growth Hormone and Growth Factors |
| Evidence tier | Preclinical |
| WADA status | Prohibited in sport (or falls under a prohibited class) — see the WADA reference table |
| Sold on this site | No — this is a reference database |
Overview
IGF-1 LR3 — a long-acting igf-1 analog — sits in the "Preclinical" tier of this catalog. The evidence base for this compound is dominated by animal and cell-culture studies. Mechanism may be plausible; human benefit and safety are unestablished.
A modified analog of insulin-like growth factor 1 with an extended half-life and reduced binding-prorotein affinity, used as a research tool in cell culture. No legitimate clinical development exists.
Mechanism of Action
The Long R3 modifications (13 Glu→Arg substitution plus N-terminal extension) reduce IGF-binding-protein affinity and extend activity, making it a potent mitogen in laboratory media.
Research and Evidence
Evidence of anabolic activity is from cell culture and animal models; no human trials of LR3 have been published.
Safety and Side Effects
Mitogenic growth-factor activity with no human safety data carries obvious theoretical oncogenic and metabolic concerns. Prohibited in sport under growth-factor rules.
Frequently Asked Questions
What is the evidence tier of IGF-1 LR3?
IGF-1 LR3 is graded "Preclinical" on this site. The evidence base for this compound is dominated by animal and cell-culture studies. Mechanism may be plausible; human benefit and safety are unestablished.
Is IGF-1 LR3 an approved medicine?
No. Preclinical means the compound has not reached universal regulatory approval; the tier description above explains exactly what level of evidence exists.
Where can I read the primary studies for IGF-1 LR3?
The references section at the end of this entry links the key primary sources — regulator labels, trial registrations, and peer-reviewed papers. Our "How to Read a Peptide Study" guide explains how to evaluate them.
References
- ClinicalTrials.gov — search for IGF-1 LR3 studies (none registered). [source]
- WADA Prohibited List — growth factors. [source]
Evidence tier: Preclinical · Last reviewed: 2026-09-05 · Sources cited below.