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Peptides · INSULIN-LIKE GROWTH FACTOR
IGF-1 LR3 1 mg
Lyophilized vial · 83 AA
IGF-1 LR3 — independently assayed, lot-tested, and shipped from our fulfillment facility in San Antonio. Released only after an independent laboratory returns its results for the lot.
Per vial
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Single- Purity Guarantee. If a lot fails our ≥99% HPLC standard, full refund + replacement.
- Lot-specific COA on demand — anytime, free
- Same reorder price — forever, no upcharge
$91.99
Single
— About this compound
IGF-1 LR3.
Class · Bioengineered IGF-1 variant with Long-R3 N-terminal extension (83 amino acids)
Origin. Developed at GroPep Limited (Adelaide, Australia) by Francis, Tomas, Wood, and colleagues in the early 1990s as a research tool with significantly extended half-life vs native IGF-1.
IGF-1 LR3 (Long R3 IGF-1) is a bioengineered analog of human insulin-like growth factor-1 carrying a 13-amino-acid N-terminal extension and an arginine substitution at position 3. The combined modifications dramatically reduce binding to IGF-binding proteins (IGFBPs).
Reduced IGFBP binding produces a substantially longer circulating half-life and higher receptor-available concentration than native IGF-1 at equivalent doses. The molecule is widely used in cell-culture research and preclinical anabolic-pathway studies.
— Common research applications
- IGF-1 receptor pharmacology
- Cell-culture anabolic research
- IGFBP binding kinetics
- Comparative IGF-variant studies
— Mechanism
How it's been studied.
IGF-1 receptor agonist with potency comparable to native IGF-1 at the receptor itself. The pharmacological distinction lies in the LR3 variant's reduced affinity for IGFBPs (particularly IGFBP-3), which extends free hormone availability in circulation and at target tissues.
Mechanism descriptions reflect findings reported in the preclinical and basic-research literature. They are not clinical conclusions and not statements of therapeutic effect.
— The Chemistry
The numbers, plainly.
CAS
—
Molecular weight
9111 Da
Formula
—
Sequence
—
Format
Lyophilized powder
Vial dose
1 mg
Purity (HPLC)
≥99%
Amino acids
83
Half-life
~5–6 hr (vs ~10–15 min for native IGF-1 in preclinical models).
Solubility
Reconstitutes in dilute acetic acid (preferred for solubility) or bacteriostatic water.
View lab results for IGF-1 LR3 → — or search any lot number from your label.
— Why Merit
The supplier difference.
How Merit compares to the two alternatives most research buyers consider for IGF-1 LR3.
Comparison reflects published facility status and standard industry practice. Compounding pharmacy availability of research peptides varies by jurisdiction.
— How it's made
From compound to your shelf.
Every Merit lot follows the same documented path. Five steps, every one verifiable.
- 01
Sourcing
Compound starts as a research-grade API.
Active pharmaceutical ingredient sourced from FDA-registered manufacturers. Identity confirmed against reference standard before any compounding begins.
- API from FDA-registered manufacturers
- Identity verified against reference standard
- Chain of custody documented
- 02
Compounding
Sterile-filled in a US cleanroom.
Lyophilized in a cleanroom at our US facility. The powder format gives ≥24 months sealed stability — no cold-chain shipping required.
- ISO-certified US facility
- ISO-certified manufacturing process
- Lyophilized powder for transit stability
- 03
Verification
Every batch HPLC-tested.
Reverse-phase HPLC-UV (UV/MS for higher-MW peptides) confirms identity and purity for every lot before it leaves the lab. The chromatogram is archived.
- Reverse-phase HPLC, per-lot
- ≥99% purity floor — every batch
- Chromatogram archived for every lot
- 04
Release
The lot is released against an independent assay.
No batch ships until an independent laboratory has returned its identity and purity results and the certificate is published against that lot number.
- Independent laboratory on every lot
- Certificate published before sale
- Lot number resolves to its own report
- 05
Dispatch
Ships from San Antonio in 48 hours.
Vials labeled with lot ID, tested date, and CAS. Order before 2pm CT Monday–Thursday for same-day dispatch. UPS Ground, tracked + insured.
- 48hr dispatch from San Antonio, TX
- Lot ID printed on every vial label
- UPS Ground, tracked + insured
Every step above can be verified for any specific lot by emailing rx@meritsciences.com with the lot number from your vial label.
— Research references
The published record.
Peer-reviewed work cited in the public scientific literature. Links resolve to PubMed or the publisher of record.
- 01
Insulin-like growth factor (IGF)-I and especially IGF-I variants are anabolic in dexamethasone-treated rats
Tomas FM, Knowles SE, Owens PC, et al. · Biochemical Journal · 1992
- 02
Use of insulin-like growth factor I analogues for the study of receptor binding and biological effects in adipocytes
Francis GL, Ross M, Ballard FJ, et al. · Journal of Molecular Endocrinology · 1992
Inclusion of a reference does not constitute a clinical claim or recommendation.
— Pairs Well With
Researchers stack this with.
The GH-Axis Stack
Secretagogue + downstream
Sermorelin paired with IGF-1 LR3 — secretagogue plus downstream growth factor in the same shipment.
$160.99 · save 10%
— Common Questions
Got questions.
What is IGF-1 LR3?+
IGF-1 LR3 (Long R3 IGF-1) is a bioengineered analog of human insulin-like growth factor-1 carrying a 13-amino-acid N-terminal extension and an arginine substitution at position 3. The combined modifications dramatically reduce binding to IGF-binding proteins (IGFBPs).
How does IGF-1 LR3 work?+
IGF-1 receptor agonist with potency comparable to native IGF-1 at the receptor itself. The pharmacological distinction lies in the LR3 variant's reduced affinity for IGFBPs (particularly IGFBP-3), which extends free hormone availability in circulation and at target tissues.
What class of compound is IGF-1 LR3?+
IGF-1 LR3 is classified as bioengineered IGF-1 variant with Long-R3 N-terminal extension (83 amino acids).
What is the reported half-life of IGF-1 LR3?+
~5–6 hr (vs ~10–15 min for native IGF-1 in preclinical models).
Why does Merit ship lyophilized?+
Lyophilized format gives ≥24 months sealed stability at -20°C — significantly longer than pre-reconstituted, which has a 30-day shelf life once in solution. You reconstitute at the moment of use, when potency is at its peak.
How do I verify my lot's COA?+
Your vial label carries the lot number. Use that number to pull the COA on our site at any time — the COA for your specific batch lives at /coa/[lot-id] and stays accessible for the life of the product.
What does "independently assayed" actually mean?+
Every lot is tested by a laboratory independent of the facility that made it, and the certificate is published before the lot is sold. You read the same identity and purity figures we do — that's what separates Merit from a reseller catalog.
Will my bank flag this purchase?+
Statements show as Merit Sciences LLC. Standard merchant descriptor — does not trigger category-code flags. All major cards and PayPal accepted at checkout.
How fast does it ship?+
48 hours from order to dispatch, Monday through Thursday. UPS Ground, tracked + insured. From San Antonio, TX, most US addresses receive within 3-5 business days.
— Talk to a Pharmacologist
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