Not medical advice. IGF-1 LR3 is a research compound. This guide does not provide dosing, diagnosis, therapy recommendations, or claims about effects in humans.
IGF-1 LR3 is investigated for IGF-receptor signalling, muscle cell culture work, and growth-factor cascades downstream of GH.
One-paragraph overview from our research datasheet — still scientific, but faster to read than the full mechanism list below.
IGF-1 LR3, 83-amino acid extended IGF-1 analogue with Arg3 substitution eliminating IGFBP binding for 3-fold enhanced potency and 20–30 hour half-life.
Peer-reviewed literature typically discusses IGF-1 LR3 in specific experimental settings. The points below reflect how the scientific community frames this compound—not as health claims, but as the research questions being asked.
Research vs. personal use: Literature describes experiments in controlled lab and animal models. This is distinct from any real-world use; our products are for laboratory research only.
Here the literature centres on muscle repair, growth-factor signalling, and how tissues respond after overload or injury in preclinical work.
Our datasheet lists mechanistic themes observed in preclinical work. These are research endpoints, not health claims. They help scientists understand and compare pathways.
Storage requirements: Lyophilised powder: store in freezer (−20 °C). Reconstituted: refrigerate 1–6 °C, away from sunlight. Use within the validated stability window for the specific batch and formulation. · Learn best practices in our detailed storage guide.
Research dosing context: Literature typically discusses 20–100 mcg subcutaneously or intramuscularly · Once daily, typically post-training or divided bilateral injections · t½ ≈ 20–30 h (vs. 12–15 h for native IGF-1); enhanced bioavailability due to <2% IGFBP binding (vs. ~98% for native IGF-1); produced via recombinant E. coli expression with chromatographic purification and refolding. Not FDA-approved, mecasermin (native rhIGF-1) is approved for pediatric primary IGFD. Banned by WADA.
Preparation steps: Follow our detailed reconstitution guide, use the calculator tool for volume confirmation, and always verify purity with the COA reading guide.
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is an 83-amino-acid analogue of human IGF-1 with an N-terminal extension and an Arg substitution at position 3. Those modifications stop it binding IGF-binding proteins, greatly extending its active half-life versus native IGF-1. It is supplied as a lyophilised research-grade powder for laboratory use only.
In research models IGF-1 LR3 activates the IGF-1 receptor (and PI3K/Akt and MAPK signalling) to drive cell growth, proliferation, differentiation and survival — with a much longer duration of action than native IGF-1 because it evades IGFBP sequestration. These are findings in cell and animal models; New-U supplies it for laboratory research only and implies no human effect.
IGF-1 LR3 is widely used as a cell-culture supplement to support proliferation and survival of cultured cells, and as a research tool for studying IGF-1-receptor signalling, hypertrophy and tissue-growth endpoints. New-U supplies it strictly for in-vitro and laboratory research; it is not for human use.
Standard employment or clinical drug panels (including typical LabCorp steroid panels) do not screen for IGF-1 LR3 — it is a peptide, not a small-molecule steroid, and requires specialised assays. It is, however, on the WADA Prohibited List, and anti-doping authorities use dedicated tests for IGF-1 analogues. New-U supplies IGF-1 LR3 for laboratory research only, not for human or athletic use.
"L" for the 13-amino-acid N-terminal extension (MFPAMPLSSLFVN), "R" for arginine, and "3" for position 3 of the IGF-1 sequence. So "LR3" literally means "the Long variant with an Arginine at position 3". Both modifications are needed to eliminate IGFBP binding and extend circulating half-life.
IGF-1 DES is the opposite end of the design spectrum - a truncated 67-residue form missing the N-terminal tripeptide GPE, which also dramatically reduces IGFBP binding. IGF-1 LR3 uses a 13-residue extension to achieve similar IGFBP resistance. LR3 has a much longer half-life (20-30 h vs minutes); DES produces more intense, shorter-duration local effects when injected site-specifically.
Native IGF-1 is inefficient in cell culture because IGFBPs produced by the cells themselves can sequester it, reducing effective concentrations. IGF-1 LR3 escapes that sequestration and delivers consistent, reproducible growth-factor signalling. That is why it is an industry standard for bioprocessing and mammalian cell culture.
Keep the lyophilised powder frozen at −20 °C. After reconstitution with bacteriostatic water, refrigerate at 1-6 °C and protect from light. IGF-1 LR3 is a structured protein and is sensitive to repeated freeze-thaw cycles - aliquot if you need multiple doses from one reconstitution.
No, and no. This article is educational only. We do not provide dosing, medical recommendations, or health claims. Our products are sold strictly for laboratory research, not for personal use of any kind.
Open the shop listing via “View product details.” There you will see batch specs, the Certificate of Analysis (COA), concentration, purity grade, and available SKUs with current pricing.
Primary literature and registries for IGF-1 LR3, plus mainstream coverage of the peptide category. Research use only - not medical advice.
Databases & literature:
Peptides in the news:
Access concentration, batch info, variants, and current pricing on our shop.
Also known as: Long R3 IGF-1, Long Arginine 3 IGF-1, IGF-1 LR3, LR3-IGF-1, Insulin-Like Growth Factor 1 Long R3, LONG R3 IGF-I, Recombinant Long R3 IGF-1