IGF-1 LR3

IGF-1 LR3 (Long R3 IGF-1) is a recombinant 83-amino-acid analogue of human insulin-like growth factor 1. It has an arginine in place of glutamic acid at position 3 and a 13-amino-acid N-terminal extension, which together greatly reduce its binding to IGF-binding proteins. It is widely used to supplement cell-culture media.

Yes. Keep the lyophilized powder refrigerated, or frozen at −20 °C for long-term storage. Once reconstituted, keep the solution refrigerated and avoid repeated freeze-thaw cycles. Many laboratory protocols reconstitute IGF-1 LR3 in a dilute acidic solution; follow the instructions on the vial label and Certificate of Analysis.

Human growth hormone (HGH, 191 amino acids) is a pituitary hormone that acts on the growth hormone receptor. IGF-1 is a separate 70-amino-acid hormone, produced largely by the liver in response to growth hormone, that acts on the IGF-1 receptor. IGF-1 LR3 is a recombinant IGF-1 analogue (83 amino acids) with an arginine at position 3 and a 13-residue N-terminal extension that reduce its binding to IGF-binding proteins. It is widely used as a supplement in cell-culture media.

IGF-1 LR3 is used mainly as a cell-culture reagent: it supplements serum-free media for mammalian cell lines, including those used in biomanufacturing. In research it serves to study IGF-1 receptor signaling, such as the PI3K–Akt and MAPK pathways, in cell culture, and it has been used in rodent studies of the IGF system. It has not been through clinical development. Findings in cells or animals do not establish effects in people.

No. IGF-1 LR3 has never been approved by the FDA. A different molecule, mecasermin (recombinant human IGF-1 with the native 70-amino-acid sequence), is an FDA-approved active ingredient, but LR3 is an engineered analogue used as a laboratory and cell-culture reagent. It is sold here for laboratory research use only.

It is a polypeptide, and at 83 amino acids it is usually called a small protein. Native IGF-1 has 70 amino acids in a single chain held by three disulfide bridges; IGF-1 LR3 adds a 13-residue N-terminal extension and an arginine at position 3. Because of its size and folded structure it is made by recombinant expression in bacteria, not by chemical peptide synthesis.

All three act on the IGF-1 receptor. IGF-1 is the native 70-amino-acid hormone, which in the body is largely bound to IGF-binding proteins. IGF-1 LR3 (83 amino acids) has an Arg3 substitution and a 13-residue N-terminal extension that greatly reduce that binding. IGF-1 DES, or des(1-3)IGF-1, is a 67-amino-acid form missing the first three residues (Gly-Pro-Glu), which also reduces binding-protein affinity.

They sit at different points of the growth hormone axis. CJC-1295, sermorelin and tesamorelin (GHRH receptor) and ipamorelin, GHRP-6 and hexarelin (ghrelin receptor) are small peptides that act on pituitary receptors controlling growth hormone release. IGF-1 LR3 acts further downstream: it is an analogue of IGF-1, the hormone produced largely in response to growth hormone, and binds the IGF-1 receptor directly.

In the United States, IGF-1 LR3 is not a controlled substance and is widely sold as a cell-culture and laboratory reagent. It is not an approved drug, so selling it for human use or with health claims is unlawful. The World Anti-Doping Agency lists IGF-1 and its analogues in class S2, prohibited in sport at all times. This is general information, not legal advice.

MGF is not a form of IGF-1 hormone itself. It is a 24-amino-acid peptide matching the E-domain, the C-terminal tail of the IGF-1Ec precursor that is cut off when mature IGF-1 is made. IGF-1 is the 70-amino-acid hormone that binds the IGF-1 receptor, and HGH is a 191-amino-acid pituitary protein. The three share no active sequence.

They are not in the same pathway. Follistatin is a binding protein that captures activin, myostatin and related TGF-β family ligands outside cells. IGF-1 LR3 acts on the IGF-1 receptor, and CJC-1295 and tesamorelin act on the GHRH receptor in the growth hormone axis. Follistatin is a large recombinant glycoprotein; CJC-1295 and tesamorelin are synthetic peptides.

IGF-1 LR3: molecular weight approximately 9,100 Da (83 residues); CAS number 946870-92-4. Sequence: 83-amino-acid analogue: MFPAMPLSSLFVN N-terminal extension fused to human IGF-1(1-70) bearing an Arg substitution at position 3 (Glu3Arg). Match these identifiers against the Certificate of Analysis for the lot.

Yes. Each lot has its own Certificate of Analysis, linked on this page for the current lot of each size: 0.1mg (99.76% HPLC purity); 1mg (99.32% HPLC purity). Past certificates are archived in the COA library; contact us with the lot number on the vial label if a certificate is missing.

99.32% (HPLC, current lot). Purity is measured by high-performance liquid chromatography (HPLC) and reported on the lot's Certificate of Analysis.

IGF-1 LR3 is supplied as lyophilized powder in a sealed vial in 2 sizes: 0.1mg, 1mg. In stock and dispatched in 1–2 business days. Quantity pricing applies automatically at 5+ and 10+ vials of the same size.

Store sealed at −20 °C, dry and protected from light.