IGF-1 LR3

What is IGF-1 LR3?

IGF-1 LR3 (Long R3 IGF-1) is an 83-amino-acid analog of human insulin-like growth factor 1. Two changes separate it from the native 70-residue protein: arginine replaces glutamic acid at position 3, and a 13-amino-acid extension is added at the N-terminus. Together these modifications sharply reduce binding to IGF-binding proteins.

That reduced binding is the reason the analog is so widely used in mammalian cell culture, where it is added to serum-free media and used to probe IGF-1 receptor signaling without interference from binding proteins in the system. At roughly 9.1 kDa it is far larger than most catalog peptides, so it is supplied in a 1 mg vial and handled more like a small protein.

Where it is used in the lab

• IGF-1 receptor signaling assays (PI3K/Akt and MAPK readouts)
• Serum-free media supplementation in mammalian cell culture
• Binding-protein interaction studies against native IGF-1

For laboratory research use only; not for human consumption.

IGF-1 LR3 specifications

Reconstitution & storage for research

Adding 1 mL of diluent to the 1 mg vial gives 1 mg/mL (1,000 µg/mL); adding 2 mL gives 0.5 mg/mL (500 µg/mL). Cell-culture work usually runs at far lower working concentrations, so plan a serial dilution: 10 µL of a 1 mg/mL stock carries 10 µg. Our reconstitution calculator runs the same arithmetic for any vial size and diluent volume.

A sterile diluent such as bacteriostatic water is the usual choice for multi-use research vials. Direct the diluent slowly down the inside wall of the vial instead of onto the powder, then swirl gently until the solution is clear. Do not shake; vigorous agitation can foam or shear the material. Use the solvent your protocol specifies for the stock, and prefer low-protein-binding tubes for dilute aliquots, since proteins of this size adsorb to standard plastic.

Storage conditions

• Unopened vial: refrigerate at 2–8 °C; move to −20 °C if the vial will sit for an extended period.
• Environment: keep the powder away from heat, moisture and direct light, and let a cold vial reach room temperature before opening so condensation does not form inside.
• After reconstitution: return the solution to 2–8 °C, label it with concentration and preparation date, and split it into aliquots if it will be sampled more than a few times.

Quality & testing

Every lot of IGF-1 LR3 is analyzed by high-performance liquid chromatography (HPLC) before release, against a specification of ≥98% purity. The result is recorded on a batch-specific Certificate of Analysis, published on our COA page, so you can match the lot number on the vial to the document before the material enters your workflow.

• Measured HPLC purity, reported as a percentage
• Identity confirmation for the compound
• Batch / lot number and analytical test date
• Supplied form and storage conditions

Vials are sealed, labeled for research use and shipped within the United States in discreet packaging. Payment is by invoice or Zelle.

Related lab guides

• IGF-1 LR3 research overview
• IGF-1 LR3 reconstitution and storage
• How IGF-1 LR3 purity is tested
• IGF-1 LR3 chemical structure and synthesis
• Reconstitution calculator guide
• HPLC vs. mass spectrometry

GHRH analogs used upstream of IGF-1 in somatotropic-axis research: Sermorelin, Tesamorelin, CJC-1295 (No DAC).