IGF-1 LR3 Research Reference

Catalog classification, reference sizes, lab math links, and source-backed data. Educational use only — not medical advice.

Researched for: LR3 IGF-1 evidence and risks

Growth Signal Research protein Lyophilized verified

Also known as: Long R3 IGF-1, IGF1 LR3

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Quick Facts

Reference Sizes

1 mg

Calculator

Preset available

Storage

Lyophilized: store at -20 deg C. After reconstitution: refrigerate 2-8 deg C; verify beyond-use timing against source COA.

Solubility

Sequence salt and formulation dependent

Catalog Description

IGF-1 LR3 (Long R3 IGF-1) is a modified IGF-1 analog with an amino acid substitution (Arg3) and a 13-amino-acid N-terminal extension that substantially reduces binding to IGF-binding proteins (IGFBPs), extending its functional half-life and receptor-activation potency relative to native IGF-1. It drives the differentiation and fusion phase of muscle regeneration, activating the PI3K/Akt/mTOR protein-synthesis pathway in existing and newly formed myofibers - mechanistically downstream of and complementary to PEG-MGF's earlier satellite-cell activation role.

Catalog descriptions reflect research context only. Not a medical claim or treatment recommendation.

Research Profile

Half-Life

Reduced IGF-binding-protein affinity changes disposition; no validated human product half-life is established

Onset

Animal glucose-lowering effects occur acutely after bolus administration

Administration Routes (Research)

Laboratory and animal researchSC or IM use is unapproved community practice

Reported Research Effects

Reduced IGFBP binding extends half-life/potency vs. native IGF-1
Activates PI3K/Akt/mTOR protein-synthesis pathway
Drives differentiation/fusion phase of muscle regeneration (downstream of MGF/PEG-MGF)

Reported Research Side Effects

Potential severe or prolonged hypoglycemia
Edema
Headache
Tissue overgrowth and mitogenic signaling
Long-term human safety is unknown

Data source: Animal comparative pharmacology, receptor-binding research, and current WADA status

Reflects preclinical/research literature context only. Not a medical claim, dosing instruction, or treatment recommendation.

Research Protocols Reported in the Literature

No validated human administration protocol has been published for LR3IGF-I [Laboratory or animal study; Not established; Not established]Source: no therapeutic human regimen

Research Interactions

Flagged Avoid / Caution Combinations (Research)

Insulin or other glucose-lowering agents
Active malignancy
Competitive sport

Reflects patterns reported in research/community literature only. Not a safety guarantee, medical advice, or interaction warning for human use.

Research Notes

Four bodybuilding injection schedules were removed. LR3IGF-I is not mecasermin and must not inherit approved recombinant IGF-1 dosing or safety claims.

Supplementary research context only. Not medical advice or a treatment recommendation.

Sources

IGF-I variant hypoglycemia study in animals — PubMed (NIH)
https://pubmed.ncbi.nlm.nih.gov/9415072/

IGF-I variant receptor-binding study — PubMed (NIH)
https://pubmed.ncbi.nlm.nih.gov/12124444/

2026 Prohibited List — World Anti-Doping Agency
https://www.wada-ama.org/en/resources/world-anti-doping-program/prohibited-list

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Research Use Only. All content is for educational and research reference only. Not medical advice, a treatment recommendation, or guidance on human use. Compounds are not FDA-approved drugs unless specifically noted.