PubMed
Insulin-like growth factor-I and its binding proteins in sport and exercise medicine
Baxter, 2011
GH SecretagoguesResearch OnlyC
IGF-1 LR3
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.
Observational report only — live community data. Not medical advice. Does not recommend doses, protocols, or treatments.
- Studies cited
- 5
- Research grade
- C
- Experience
- 99
- Activity
- 49
Overall check-ins
Trackers & reports
Overview
About IGF-1 LR3
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.
- Category
- GH Secretagogues
- Regulatory status
- Research Only
- Also known as
- Long R3 IGF-1
- Self-reports
- 30
Community
What 30 users report
30 community reports
Overall experience
From check-in ratings — separate from side effects logged below. Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Favorable 97% · Mixed 3% · Unfavorable overall 0%
Most reported benefits
Benefits users selected when logging a favorable or mixed check-in.
Recovery
171
Most logged side effects
Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Water retention
5
Self-reported dose per injection
Median bucket: 50–100 mcg · Most common: 10–25 mcg
Reports span 0–200 mcg
0–10
1
10–25
60
25–50
1
50–100
53
100–200
56
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
Commonly stacked with
How repeat users are trending
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
Cited research (4)
Source
ClinicalTrials.gov
IGF-1 LR3 studies on ClinicalTrials.gov
ClinicalTrials.gov, 2024
PubMed
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
Engel et al., 2025
PubMed
Revolutionary decellularized Alstroemeria stem-based nerve conduit integrated with GelMA and controlled IGF-1 LR3 release for enhanced rat sciatic nerve regeneration
Yavuz et al., 2025
Tools
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More ways to learn about IGF-1 LR3 from observational PeptIQ data.
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Frequently asked
What do PeptIQ users report about IGF-1 LR3?
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.
How do side effects relate to overall experience for IGF-1 LR3?
PeptIQ separates overall check-in ratings (favorable, mixed, or unfavorable) from logged side effects like nausea or fatigue. Users often report benefits and side effects in the same check-in — a high experience score does not mean zero side effects were noted.
What research is cited for IGF-1 LR3?
4 sources are linked on this page, including PubMed articles, clinical trial registries, and FDA labels where applicable. Citations describe published research — not recommendations.
Is IGF-1 LR3 safe to use?
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.
What are the purported benefits and uses of IGF-1 LR3?
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.
SourceWhat is the legal status of IGF-1 LR3?
IGF-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.
SourceWhat are the known or theoretical side effects and risks of IGF-1 LR3?
The 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.
SourceWhat is the current state of research on IGF-1 LR3?
While 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