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IGF-1 LR3 1 mg supplied as a lyophilised vial. Tested at 99.7% purity by an independent laboratory. Certificate published under lot COA5495.
98+
Every lot has a certificate from an independent laboratory, typically for HPLC purity and identity.
1–3
Orders are usually prepared for shipment within 1–3 business days, then tracked end to end.
COA
Read the latest certificate for the compound before you place the order, not after.
Certificate of analysis
The certificate of analysis an independent laboratory issued for the lot listed here: typically purity by HPLC and identity, and endotoxins where the laboratory tested them.
Lyophilised powder is stable at ambient temperature in transit. On arrival, keep sealed vials refrigerated at 2–8 °C, dry and dark. For storage beyond three months, keep at −20 °C.
Follow your laboratory's own protocol.
Refrigerate at 2–8 °C and protect from light. Use within 30 days. Discard if the solution becomes cloudy or discoloured.
For laboratory research use only. Not for human or veterinary consumption. Not a drug or dietary supplement.
Research record
IGF-1 LR3 (Long R3 IGF-I) is a recombinant 83-residue analogue of insulin-like growth factor I: the human sequence with arginine in place of glutamate at position 3 and a 13-residue N-terminal extension. The changes sharply reduce binding to the IGF-binding proteins, and the analogue was engineered for use in mammalian cell culture.
01
The analogue was one of a series of IGF-I fusion peptides carrying the first 11 amino acids of methionyl porcine growth hormone at the N-terminus. In myoblasts all were more potent than IGF-I; in cell lines that secrete IGF-binding proteins the arginine-3 form was the most potent, while in fibroblasts that secrete none it was less potent than IGF-I. The authors attribute the added potency to reduced binding-protein interaction rather than to the receptor.
02
In rats made catabolic with dexamethasone the analogue was about 2.5-fold more potent than IGF-I on body weight and nitrogen retention, although it binds the type 1 IGF receptor three-fold less well. The same property shortens its stay: with little binding-protein association it is cleared from the circulation and from wound fluid faster than IGF-I.
03
Responses differ by species: in finisher pigs an infusion reduced growth, food intake and plasma growth hormone, IGF-binding protein-3, IGF-I and insulin, and in guinea pigs it lowered circulating IGF-I, IGF-II and binding proteins. In serum-free culture it supports Chinese hamster ovary cells at concentrations at least 200-fold lower than insulin, and activates both the IGF-I and the insulin receptor in HEK293 cells.
| Research area | Assay |
|---|---|
| Receptor activation | IGF-I and insulin receptor phosphorylation in HEK293 cells |
| Cell culture | Serum-free growth of CHO and HEK293 cells |
| Binding proteins | IGFBP interaction and its effect on potency in secreting cell lines |
| Anabolic models | Nitrogen retention and protein turnover in catabolic rats |
| Clearance | Plasma and wound-fluid clearance of labelled IGFs |
Because it escapes the binding proteins, the analogue is not regulated the way IGF-I is, and in several animal models it lowered endogenous IGF-I, growth hormone or insulin; growth responses in pigs were negative. It was engineered as a cell-culture reagent. Anti-doping laboratories have identified it in products sold outside research channels, including a His-tagged form made for biochemical studies. It holds no FDA approval.
Regulatory status as of October 2026.
Ordering, handling and compliance. Anything not covered here, write to support@pureforgelabs.com.
Every compound we sell is supplied for laboratory research and development only. It is not a drug, not a supplement, and not intended to diagnose, treat, cure or prevent any condition in humans or animals. Buying from this site means you are acquiring it for in vitro or other controlled research work.
Purchasers must be 21 or older and are responsible for compliance with the law where they take delivery. We ship to research institutions, laboratories and qualified individual researchers in the United States only. We do not ship to jurisdictions where these compounds are restricted.
Check three things in order. First, the lot code on the certificate matches the lot listed on the product page and in your order. Second, where the report gives an HPLC purity, its chromatogram shows a single dominant peak at the stated figure; a blend's report shows a peak for each compound. Third, where the lab ran mass spectrometry, the measured mass matches the expected molecular weight of the compound. Anything that does not line up, send us the lot code.
Unopened vials keep at ambient temperature short term, as in transit; on arrival, refrigerate them at 2–8 °C, and keep them at −20 °C beyond three months. Reconstitute following your laboratory's own protocol; once in solution, refrigerate at 2–8 °C, protect from light and use within 30 days.
Orders are normally prepared for shipment within 1–3 business days and ship to street addresses in the United States only — not to P.O. boxes or APO/FPO/DPO military addresses. Shipping is free on orders over $150 and a flat $14.95 below that.
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Keep the vial and all the packaging, photograph the damage and email support@pureforgelabs.com within 48 hours of delivery with your order number. Once the claim is verified, we replace the vial or refund what you paid for it. Please do not send anything back unless we ask you to — apart from damaged or incorrect items, all sales are final.
Yes, by quote. The volume tiers on the product pages go up to five vials; for larger research quantities email support@pureforgelabs.com with the compounds and amounts, and we will quote per gram.
FOR RESEARCH USE ONLY. NOT FOR HUMAN OR VETERINARY CONSUMPTION. This product is intended solely for legitimate laboratory, analytical, and scientific research. It is not intended to diagnose, treat, cure, mitigate, or prevent any disease and is not intended for human or veterinary administration or consumption. All products are intended for research and identification purposes only. These products are not intended for human dosing, injection, or ingestion.
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Damaged in transit, or not the product on your order? Email support@pureforgelabs.com within 48 hours of delivery with photos of the item and the package — once verified, we replace it or refund it. All other sales are final.
All compounds are sold for in-vitro laboratory research only. Not for human or veterinary use, not a drug or dietary supplement. By placing this order you confirm you are a qualified researcher aged 21 or over and that the material will not be administered to humans or animals.
