Lot-Documented
HPLC-Verified
US Pharmacist
Same Reorder Price
Peptides · INSULIN-LIKE GROWTH FACTOR
IGF-1 LR3 1 mg
Lyophilized vial · 83 AA
IGF-1 LR3 — pharmacy-verified, lot-tested, and shipped from our facility in Dallas. Released only after a US-licensed pharmacist signs off on the batch.
Per vial
Select your pack size
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.
— 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
Sign-off
A US-licensed pharmacist releases the lot.
No batch ships without a pharmacist reviewing the chromatogram, identity report, and lot documentation. The pharmacist holds the release authority.
- US-licensed pharmacist on every lot
- Pharmacist holds release authority
- No batch ships unsigned — ever
- 05
Dispatch
Ships from Dallas 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 Dallas, 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 "pharmacy-verified" actually mean?+
A US-licensed pharmacist on our team reviews every batch before release. They sign off on the lot's purity, identity, and release. No batch ships without that sign-off — and 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 Dallas, TX, most US addresses receive within 3-5 business days.
— Talk to a Pharmacologist
Question we didn't answer?
Our team answers compound questions, lot questions, and protocol questions — same business day. No bots, no tickets.
Email the team →
