IGF-1 LR3
Tissue & recoveryAlso known as Long R3 IGF-1, IGF-1 Long R3
Evidence tier
Some human data
1 human trial
- Researched since
- 1993
- Publications
- 49
- Mean purity
- 99.2%
- Vendors listing
- 12
American Peptides shows the highest mean assayed purity for IGF-1 LR3 at 99.9% across 1 lot record. Purity figures below come from the certificates named in each row.
Score breakdown
The score has two halves: the research base — how long the compound has been studied and how much has been published — and the quality of the evidence the market produces for it, aggregated across every vendor that carries it: assayed purity, lot-to-lot consistency, readable third-party certificates and those vendors’ review record. It measures the evidence base, not the merits or safety of the substance.
Studied since 1993 — 33 years of published research
How long the compound has been studied. Fifteen years or more of published literature earns full marks; a newer compound earns less.
49 publications indexed in PubMed
The volume of published literature located. Full marks at fifty or more publications.
Mean assayed purity 99.2% across 6 certificates
Average assayed purity on the certificates published by vendors that carry this compound. Full marks at 99.5%+, nothing at 95% or below.
±0.50 pts purity across lots, mean label deviation 19.3%
How tightly assayed purity and labeled-versus-actual mass hold across different lots. Rewards reproducible manufacturing.
12 of 12 listing vendors publish an accessible certificate policy
Whether the vendors carrying this compound publish per-lot certificates anyone can read without an account.
6 of 6 certificates from a recognised independent lab
Share of certificates issued by a recognised third-party testing lab rather than an unnamed or self-named one.
What is IGF-1 LR3?
A modified, longer-acting analogue of insulin-like growth factor 1, altered to extend its half-life and reduce binding to carrier proteins. It is a common cell-culture reagent.
Studied in published research for muscle growth and tissue development.
Regulatory status
Labeled by vendors for laboratory research use only. Not approved as a medicine in the United States, United Kingdom, or European Union.
What the research examines
The areas of published research this compound appears in. These describe what the literature has studied — never a claim of benefit, effect or suitability for any use.
Published research
Published work is largely preclinical and in cell culture, where it is widely used as a research reagent. PepIndex does not evaluate clinical significance and does not describe administration.
- Recombinant expression of IGF-1 and LR3 IGF-1 fused with xylanase in Pichia pastoris — Applied microbiology and biotechnology (2023)
Peer-reviewed article indexed in PubMed, published in Applied microbiology and biotechnology (2023).
- IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheep — American journal of physiology. Endocrinology and metabolism (2025)
Peer-reviewed article indexed in PubMed, published in American journal of physiology. Endocrinology and metabolism (2025).
- Attenuated glucose-stimulated insulin secretion during an acute IGF-1 LR3 infusion into fetal sheep does not persist in isolated islets — Journal of developmental origins of health and disease (2023)
Peer-reviewed article indexed in PubMed, published in Journal of developmental origins of health and disease (2023).
- Revolutionary decellularized Alstroemeria stem-based nerve conduit integrated with GelMA and controlled IGF-1 LR3 release for enhanced rat sciatic nerve regeneration — International journal of biological macromolecules (2025)
Peer-reviewed article indexed in PubMed, published in International journal of biological macromolecules (2025).
- Intranasal long R3 insulin-like growth factor-1 treatment promotes amyloid plaque remodeling in cerebral cortex but fails to preserve cognitive function in male 5XFAD mice — Journal of Alzheimer's disease : JAD (2025)
Peer-reviewed article indexed in PubMed, published in Journal of Alzheimer's disease : JAD (2025).
- Sheep recombinant IGF-1 promotes organ-specific growth in fetal sheep — Frontiers in physiology (2022)
Peer-reviewed article indexed in PubMed, published in Frontiers in physiology (2022).
- Action of long(R3)-insulin-like growth factor-1 on protein metabolism in beef heifers — Domestic animal endocrinology (1999)
Peer-reviewed article indexed in PubMed, published in Domestic animal endocrinology (1999).
- Coronary vascular growth matches IGF-1-stimulated cardiac growth in fetal sheep — FASEB journal : official publication of the Federation of American Societies for Experimental Biology (2020)
Peer-reviewed article indexed in PubMed, published in FASEB journal : official publication of the Federation of American Societies for Experimental Biology (2020).
Indexed studies1 human-evidence of 1
- Differential effects of insulin-like growth factor-I and gonadotropins on the proliferative activity of two subgroups of granulosa cells: cumulus oophorus and mural granulosa cells — Human — controlled trial, 2001
To evaluate the physiological role of insulin-like growth factor-I (IGFI) and its interaction with gonadotropins in cell replication of two types of granulosa cells (cumulus oophorus, CC) and mural granulosa cells (MGC). Controlled randomized study of the action and interaction of gonadotropins and IGFI on granulosa cell replication in the rat. A university reproductive biology laboratory. The study examined the in vivo treatment with gonadotropins or an analogue of IGFI, lon…
Evidence digest
What the research on IGF-1 LR3 actually shows
The indexed literature on IGF-1 LR3 includes human clinical or observational records (1 human-clinical or observational record). This digest describes the shape of that evidence and links the records behind it. It does not judge whether IGF-1 LR3 is safe or effective for any purpose, and nothing here is medical advice — the material sold by the vendors in this index is labeled for laboratory research use only.
3 things the literature does not establish →
PepIndex describes what literature exists. We do not interpret it, assess clinical significance, or publish quantities, protocols or instructions for use.
Vendor comparison
| Vendor | Score here | Price / mg | Certificates | Mean purity | Label deviation | Get it |
|---|---|---|---|---|---|---|
| PeptidePlugs | 89.790% | — | 1 | 99.1% | 26.0% | |
| American PeptidesISO/IEC 17025 | 86.5100% | $85.00 (100%) | 1 | 99.9% | 21.0% | |
| Northline LabsISO/IEC 17025 | 79.493% | — | 1 | 98.3% | 4.0% | |
| Evo Labs Research | 79.289% | $69.99 (82%) | 0 | — | — | |
| NeuroLabs Research | 78.186% | $84.95 (100%) | 0 | — | — | |
| Licensed Peptides | 7789% | — | 1 | 99.0% | 7.9% | |
| Modern AminosISO/IEC 17025 | 74100% | — | 1 | 99.6% | 29.0% | |
| Mile High Compounds | 71.194% | $8.00 (30%) | 0 | — | — | |
| Vertex Labs | 70.170% | — | 1 | 99.2% | 28.0% | |
| GenX Peptides | 68.168% | $85.00 (100%) | 0 | — | — | |
| Eternal Peptides | 67.265% | $79.99 (94%) | 0 | — | — | |
| Sports Technology Labs | 58.574% | $124.99 (147%) | 0 | — | — |
Certificate records
| Vendor | Lot | Tested | Lab | Labeled | Assayed | Discrepancy | Purity | Source |
|---|---|---|---|---|---|---|---|---|
| Northline Labs | NLL-5439587 | ILS Laboratories | 1 mg | 1.04 mg | 4.0% | 98.3% | Vendor-published | |
| Modern Aminos | BX-P-Z7C7 | Analysis FreedomDiagnostics | 1 mg | 1.29 mg | 29.0% | 99.6% | Vendor-published | |
| American Peptides | IGF-0528 | Bioviridian Inc. | 1 mg | 1.21 mg | 21.0% | 99.9% | Vendor-published | |
| PeptidePlugs | 140-01-DK | Freedom Diagnostics Testing | 1 mg | 1.26 mg | 26.0% | 99.1% | Vendor-published | |
| Vertex Labs | 2605010111 | Freedom Diagnostics Testing | 1 mg | 0.72 mg | 28.0% | 99.2% | Vendor-published | |
| Licensed Peptides | IGF1LR3-01 | Vanguard Laboratory | 100 mg | 92.07 mg | 7.9% | 99.0% | Vendor-published |