Muscle Growth Research Market

IGF-1 LR3

A long-acting insulin-like growth factor analog discussed in physique and performance communities rather than approved peptide medicine.

IGF-1Muscle GrowthPerformanceLong-Acting

Also referenced as: Long R3 IGF-1

Also appears in: Growth Hormone

Price compare
45 tracked offers across 45 vendors · 10 dosages
Best trust-adjusted value: Peptide Supply Co · Strong trust · $34.20/mg
From
$34.20/mg
Status
Research Market

This name primarily lives in the research market and should not be read like an approved pharmaceutical product.

Category
Muscle Growth

Primary lane: Muscle Growth. Also surfaces under Growth Hormone for browsing and discovery.

Aliases
1

Long R3 IGF-1

Signal depth
Low

No FDA label signal · 0 trials · 17 PubMed results

Preclinical
Research evidence

Current evidence for IGF-1 LR3 is limited to laboratory or animal studies — there are no name-matched human trials with reported results. Any claims about effects in people are not yet backed by clinical data.

IGF-1 LR3 has no clinical trials that name it and 12 PubMed-indexed publications and is not FDA-approved. Current evidence is preclinical or mechanistic.

Human data
Lab / animal only
Trial quality
No human trials
Outcomes
No human trials
Replication
Multiple papers
Literature
Emerging
American Journal of Physiology-Endocrinology and Metabolism · 3 citations IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheep International Journal of Biological Macromolecules · 2 citations Revolutionary decellularized Alstroemeria stem-based nerve conduit integrated with GelMA and controlled IGF-1 LR3 release for enhanced rat sciatic nerve regeneration Journal of Developmental Origins of Health and Disease · 1 citations Attenuated glucose-stimulated insulin secretion during an acute IGF-1 LR3 infusion into fetal sheep does not persist in isolated islets Journal Article The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration. Journal Article Provisional Treatment of Volumetric Muscle Loss With Insulin-like Growth Factor 1 Releasing Muscle Void Fillers. Journal Article 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.
Evidence history

Re-checked nightly against the registries — tracked since 2026-07-09. No band changes yet.

Grades evidence strength, not efficacy or safety. Research-use context; not medical advice. Graded 2026-07-13 from PubMed, ClinicalTrials.gov, ISRCTN, openFDA, Health Canada, and OpenAlex — computed deterministically and refreshed nightly, with a retraction check. How we grade →

What IGF-1 LR3 is

IGF-1 LR3 is a modified insulin-like growth factor analog designed for a longer activity profile than native IGF-1. It is usually discussed in physique, recovery, and performance circles rather than in standard FDA-approved therapeutic practice.

Why it matters

This profile belongs in the library because “muscle growth peptides” is one of the most searched peptide buckets online, and readers need at least one clearly labeled example of that category.

Regulatory context

IGF-1 LR3 is not an FDA-approved peptide therapy in the way licensed medicines are. It should be read as a research-market/performance-adjacent compound, not as a mainstream medical treatment.

Practical reading note

This is exactly the kind of profile where category clarity matters: muscle-growth demand is high, but evidence quality, legality, and product quality are all much messier than the marketing usually implies.