IGF-1 LR3
Long R3 IGF-1 · LR3-IGF-1 · Long Arg3 Insulin-like Growth Factor-1
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At a glance
- Muscle Growth
- 7/10
- Recovery
- 7/10
- Strength
- 4/10
- Endurance
- 2/10
- Fat Loss
- 1/10
- Cognition
- 1/10
Overview
IGF-1 LR3 is a modified analogue of insulin-like growth factor 1, studied for its effects on growth-factor signaling and cell growth. Its reduced interaction with IGF-binding proteins is central to laboratory research. Fitness communities also discuss LR3 for muscle growth and recovery. This guide separates those reports from the experimental evidence and explains how LR3 differs from native IGF-1 and DES.
Structural research identifies an amino-acid substitution and a 13-residue extension. Francis and colleagues compared the activity of IGF-I analogues in cell systems. These findings explain research interest without establishing a human bodybuilding regimen.
Compare native IGF-1 with LR3, or compare LR3 research suppliers.
How IGF-1 LR3 works
What the LR3 modification changes#
LR3 has 83 amino acids, including an extension and an arginine substitution relative to native IGF-1. Laajoki 2000 studied its structure. Francis 1992 found stronger protein- and DNA-synthesis activity for the analogues than native IGF-I in rat muscle-cell cultures. Relative activity changed in other cell systems, emphasizing the role of binding proteins.
What animal research adds#
Tomas 1992 found anabolic effects of IGF-I and its variants in dexamethasone-treated rats, including changes in body weight, nitrogen retention and protein turnover. LR3 and DES were more potent than native IGF-I in that model. These findings explain the research interest; human muscle-gain results require separate evidence.
Native-IGF studies are background, not LR3 pharmacokinetics#
Guler 1989 measured free and protein-bound native IGF tracers. It does not establish a 20–30-hour human LR3 half-life. A compound's biological effects, laboratory persistence and human elimination half-life are different measurements.
Protocol
IGF-1 LR3 dosage: what the references establish#
| Evidence | Material and context | Interpretation |
|---|---|---|
| Francis 1992 | IGF-I analogues in cell systems | Experimental activity, not a human dose ladder |
| Tomas 1992 | IGF-I variants in treated rats | Animal findings, not a bodybuilding schedule |
| Community discussion | Personal discussion of several growth-related compounds | Context for user interest; molecule, co-use and outcomes need checking |
These sources do not establish an optimal human LR3 dose. Numeric schedules reported elsewhere should be attributed to their original report and kept separate from clinical recommendations. Mecasermin instructions apply to a different product.
For laboratory measurements, the peptide calculator converts the inputs supplied; it does not choose a dose or validate a preparation. Compare LR3 product listings for the exact material and vial strength.
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Cycle length & outcomes
LR3 cycle length and timing#
Bodybuilding discussions often focus on cycle length, workout timing and combinations. The community discussion includes several distinct compounds; it should not be treated as one agreed protocol.
The cell study and rat study do not establish a four-to-six-week human cycle ceiling, a required break of equal length, or a point at which all gains stop. Those would require their own evidence.
Read a reported schedule alongside the exact molecule, formulation, other substances used and outcomes measured. Keep LR3 reports separate from native IGF-1 and DES.
Risks & mistakes
What the cited evidence can tell us#
The cited cell and animal studies do not establish human adverse-event rates or a maximum tolerated LR3 dose. Native-IGF clinical findings should remain labelled as findings about that molecule and formulation.
Glucose effects deserve attention: recombinant human IGF-1 lowered glucose in a small human experiment. This is not a direct LR3 safety estimate, and a forum account cannot establish that combining LR3 with insulin is safe.
Seek medical assessment for symptoms after exposure. Loss of consciousness, seizures or breathing difficulty require urgent help.
Stack & combine
Multipliers applied when these compounds run together. Values > 1 indicate a bonus on that axis. Tap a partner to expand the mechanism.
Pharmacokinetic conflicts, competing pathways, or compounded toxicity. Multipliers below 1 indicate the affected axis.
| Partner | Type | Lean | Fat loss | Recovery |
|---|---|---|---|---|
| antagonistic | ×0.95 | ×0.92 | ×0.98 |
FAQ — IGF-1 LR3
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Research & citations
5 studies cited on this page.
Conclusion
LR3 is a distinct research analogue with structural, cell and animal evidence to examine. Keep the molecule and experimental setting attached to each finding when comparing it with native IGF-1, DES or community reports.
Compare native IGF-1 and LR3, review the dosage context, or compare LR3 research suppliers.
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Disclosures
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