IGF-1 LR3 research peptide
What is IGF-1 LR3?
IGF-1 LR3 (Long R3 IGF-1) is an 83-residue analog of insulin-like growth factor 1. It differs from the 70-residue native IGF-1 in two ways: a 13-residue extension (MFPAMPLSSLFVN) at the N-terminus, and arginine in place of glutamate at position 3 of the IGF-1 sequence, which is the "R3" in the name. Both changes greatly reduce binding to IGF-binding proteins while leaving the IGF-1 receptor (IGF1R) binding region intact, which is why the analog is widely used in cell-culture research.
IGF-1 LR3 Labs supplies it as a lyophilized powder in 1 mg vials. Each lot is tested by ILS Laboratories for HPLC purity, identity against a reference standard and net content, with a fentanyl screen, and the certificate is published here before sale through Klow.bio.
Structural features that matter for analysis
The molecule contains six cysteines that form three intramolecular disulfide bonds, as in native IGF-1, so its folded structure matters as much as its sequence. The formula and molecular weight shown assume all three disulfides are formed. At about 9.1 kDa it is the largest product in this range.
Sizes and ordering
IGF-1 LR3 is supplied as a lyophilized powder in 1 mg vials. It is sold through klow.bio, operated by Klow Labs LLC, where current pricing, bundle discounts and shipping options are listed. Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout.