PubMed
Insulin-like growth factor-I and its binding proteins in sport and exercise medicine
Baxter, 2011
Long R3 IGF-1
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a recombinant analog of IGF-1 with an Arg3 substitution and a 13-amino acid N-terminal extension. These modifications dramatically reduce binding to IGF-binding proteins (IGFBPs), resulting in a ~20–30 hour half-life (vs. 12–15 hours for native IGF-1) and significantly greater tissue exposure and anabolic potency. Research only; not FDA-approved.
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Overview
IGF-1 LR3 (Long R3 Insulin-like Growth Factor-1) is a recombinant analog of IGF-1 with an Arg3 substitution and a 13-amino acid N-terminal extension. These modifications dramatically reduce binding to IGF-binding proteins (IGFBPs), resulting in a ~20–30 hour half-life (vs. 12–15 hours for native IGF-1) and significantly greater tissue exposure and anabolic potency. Research only; not FDA-approved.
Community
Positive 97% · Neutral 3% · Negative 0%
Median: 50–100 mcg · Most common: 0–25 mcg
Among repeat reporters, 96% said they felt similar to their last entry, 4% more positive, and 0% more negative.
Overall, repeat reporters leaned more positive than their previous entry.
Median gap between entries: 153 days · Based on 28 repeat reporters
Research
PubMed
Baxter, 2011
Help
This page summarizes 30 anonymized self-reports from PeptIQ users who track IGF-1 LR3, including commonly reported effects and co-tracked peptides. These are observational patterns, not clinical outcomes.
1 sources are linked on this page, including PubMed articles, clinical trial registries, and FDA labels where applicable. Citations describe published research — not recommendations.
This wiki does not assess safety or recommend use. IGF-1 LR3 is listed as Research Only. Consult a licensed clinician for personal medical decisions.
Research, primarily in animal models, suggests IGF-1 LR3 may have a wide range of therapeutic potentials due to its ability to promote angiogenesis (formation of new blood vessels), stimulate collagen synthesis, and modulate inflammatory responses.
SourceIGF-1 LR3 is not approved by the FDA for any human use. There is no legal basis for selling it as a drug, food, or dietary supplement in the United States. The FDA has classified IGF-1 LR3 as a Category 2 bulk drug substance, which explicitly prohibits licensed compounding pharmacies from using it in compounded medications.
SourceThe safety and effectiveness of IGF-1 LR3 have not been thoroughly evaluated in humans through rigorous clinical trials. This lack of human data means that safe dosages, short-term side effects, and long-term health consequences are largely unknown.
SourceWhile there are over 200 published studies on IGF-1 LR3, the vast majority are animal or in vitro (cell) studies. These preclinical studies consistently show positive results across various tissue types. However, there is a significant lack of comprehensive human clinical trial data.
Source