Peptides
IGF-1 LR3
IGF-1 LR3 is a long-acting analog of insulin-like growth factor 1 studied in muscle-growth research. Below, we compare vendors currently stocking research-grade IGF-1 LR3 — not just a single sales page.
IGF-1 LR3 is a long-acting analog of insulin-like growth factor 1 studied in muscle-growth research. Below, we compare vendors currently stocking research-grade IGF-1 LR3 — not just a single sales page.
Prices and testing claims are pulled from each vendor's product listing. Always confirm current price and COA (Certificate of Analysis) on the vendor's site before buying.
| Vendor | Price | Purity Testing | Code | |
|---|---|---|---|---|
 SwissChemsBest Value |
$59.96 – $599.60 | Third-party COA | Buy Here → | |
 Amino Club |
From $69.99 | Third-party COA | Buy Here → | |
 Amino Vault |
$74.80 | Third-party COA | Buy Here → | |
 MuscleChem |
£59.99 | In-house testing | Buy Here → | |
 American Peptides |
$85.00 | Third-party COA | Buy Here → |
IGF-1 LR3 (Long Arg3-IGF-1) is a synthetic, modified analog of endogenous Insulin-like Growth Factor-1, engineered with an extended amino-acid sequence and substitution at the third residue that reduces its binding to IGF-binding proteins.
Research-grade IGF-1 LR3 is typically supplied as a lyophilized powder in sealed vials, commonly at 1mg strength, intended for laboratory reconstitution and research use only.
By reducing affinity for IGF-binding proteins, IGF-1 LR3 remains more bioavailable to IGF-1 receptors than native IGF-1 in experimental systems, a property researchers have used to study amplified downstream growth-signaling effects compared to unmodified IGF-1.
IGF-1 receptor activation is strongly associated with cellular growth and protein-synthesis pathways, and IGF-1 LR3's extended bioavailability has made it a common tool in cell-growth and hypertrophy-signaling research.
Because IGF-1 LR3's altered binding-protein interaction distinguishes it from native IGF-1, it is frequently used in research examining how free versus bound IGF-1 differentially activates receptor signaling.
IGF-1 LR3 is not FDA-approved and has not been evaluated in controlled human trials. Reported concerns associated with excess IGF-1 signaling in the broader endocrine literature include hypoglycemia risk, fluid retention, and theoretical concerns about unchecked cell proliferation, none of which have been systematically studied for this specific analog in humans.
Doses used in cell-culture and animal research vary by study design and are not established as a human protocol. No FDA-approved human dosage exists for IGF-1 LR3.
Compound X does not sell IGF-1 LR3 directly. We provide independent research, comparisons and vendor links — see the vendor comparison table above for current US, UK, Canada and Australia options.
IGF-1 LR3 research is indexed on PubMed under search terms such as "Long R3 IGF-1" and "IGF-1 analog receptor binding protein."
New guides, vendor comparisons and compound breakdowns every week.