Peps
What is IGF-1 LR3?
IGF-1 LR3 is a modified IGF-1 analogue. A rat experiment assessed intestinal tissue growth and glucose-analogue absorption, rather than bodybuilding outcomes.
Biological role or research focus
Intestinal growth and absorption models.
The normalization matters: more tissue is different from greater function per unit of tissue. No human strength or athletic benefit was tested.
Names you may encounter
Long R3 IGF-1 · LR3 IGF-1
Search terms can include brands, combinations, or historical names. They are not automatic product equivalents.
- Class / identity
- Modified long-R3 IGF-1 analogue
- Research focus
- Intestinal growth and absorption models
- Featured evidence
- Animal study
- Source check
- October 4, 2026
Biology & proposed mechanism
The study examined tissue responses to growth-factor exposure. Larger tissue mass can change total absorption without improving absorption per unit of tissue.
Research context & identity
This page distinguishes LR3 from DES and native IGF-1. Different analogues cannot inherit each other’s effects or safety findings.
What does the evidence show?
Selected published evidence, with the population, findings, and limits kept together. These original summaries draw on publication abstracts; they are not a systematic review.
Animal study · 2002
Long-R3 IGF-1 and rat intestinal absorption
What did this publication test, and what did it find?
- Population / model
- Rats receiving seven-day experimental infusions.
- Study design
- Comparison of native IGF-1, long-R3 IGF-1, and vehicle, followed by jejunal tissue and absorption measurements.
- Main finding
- Mucosal mass and absorption per length of intestine increased. The absorption difference was no longer significant when expressed relative to tissue weight.
- Limits & context
- The normalization matters: more tissue is different from greater function per unit of tissue. No human strength or athletic benefit was tested.
Read the original paper for methods, adverse events, funding, and conflicts of interest. Publisher access may require a subscription.
Further reading · 4 additional publication links
Exact-name PubMed search checked 2026-10-04. These records have not been appraised. A name match can include related compounds, combinations, or other formulations; it does not establish safety or benefit.
IGF-1 LR3 does not promote growth in late-gestation growth-restricted fetal sheep. ↗
American journal of physiology. Endocrinology and metabolism · 2025 Jan 1 · Journal Article
Read available full text ↗
Recombinant expression of IGF-1 and LR3 IGF-1 fused with xylanase in Pichia pastoris. ↗
Applied microbiology and biotechnology · 2023 Jul · Journal Article
Attenuated glucose-stimulated insulin secretion during an acute IGF-1 LR3 infusion into fetal sheep does not persist in isolated islets. ↗
Journal of developmental origins of health and disease · 2023 Jun · Journal Article, Research Support, N.I.H., Extramural
Read available full text ↗
Revolutionary decellularized Alstroemeria stem-based nerve conduit integrated with GelMA and controlled IGF-1 LR3 release for enhanced rat sciatic nerve regeneration. ↗
International journal of biological macromolecules · 2025 Nov · Journal Article
New editorial updates
New source discoveries
Links appear automatically. Unreviewed discoveries are not verified medical findings.
Safety & precautions
Safety & what remains unknown
A short animal infusion experiment cannot establish safety for human metabolic or tissue-growth effects.
Evidence boundaries
The normalization matters: more tissue is different from greater function per unit of tissue. No human strength or athletic benefit was tested.
This is not a complete list of contraindications, interactions, or adverse effects. Medicine labels apply to specific products and indications; research-use listings are not interchangeable with approved medicines.
What are people discussing?
No editorial transcript note has been reviewed for this profile yet. Below are the matching video records available for exploration; title and caption matches are not verified claims.
Watch the source discussions
2 matching video records · 0 with captions indexed.
Across the full library, 30 caption files are indexed from 20,199 inventoried videos. Most transcripts remain unreviewed. Select a thumbnail or timestamp to watch inside PepsRadar. Thumbnail images load from YouTube.
Biohackingturkey
IGF-1 LR3 Nedir? Kas Gelişiminde Gerçekten İşe Yarıyor mu? ↗
Title match · Captions not indexed
Peptide Of The Week
Peptide Q&A #58 – Shelf Life, Drug Test, HGH vs IGF-1 LR3 & Carnivore Diet ↗
Title match · Captions not indexed
Sources & supplier listings
Listings are grouped by the vendor’s stated identity. Blends and modified derivatives are labeled separately. Inclusion is not a quality assessment or an endorsement.
IGF-1 LR3 (1 mg)
American Peptides · Vendor-labeled research use only
$85.00
Listed in stock · Snapshot 2026-10-05
Options may vary. Shipping and tax excluded.
Affiliate link · PepsRadar may earn a commission from purchases through this link. Affiliate disclosure.
IGF-1 LR3 (0.1 mg / 1 mg)
PSPeptides · Vendor-labeled research use only
$24.99–$89.99
Listed in stock · Snapshot 2026-10-05
Options may vary. Shipping and tax excluded.
Affiliate link · PepsRadar may earn a commission from purchases through this link. Affiliate disclosure.
Catalog checked 2026-10-04. Seller listings retain their stated intended use. Shops covered: BioLongevity Labs, BioLongevity Supplements, American Peptides, PSPeptides. This is not a market-wide comparison. Affiliate participation does not determine evidence or editorial coverage.
Questions worth asking
- Did the study show better absorption per unit of tissue?
- What material, population, and route were actually studied?
- The normalization matters: more tissue is different from greater function per unit of tissue. No human strength or athletic benefit was tested.
- What adverse effects, uncertainty, and conflicts of interest does the original source report?
Frequently asked questions
Did the study show better absorption per unit of tissue?
The reported difference lost significance when normalized to tissue weight. The main observation included increased mucosal mass.
Does the publication verify a supplier’s product?
No. The tested material and a commercial listing need separate identity and batch checks. A research-use disclaimer does not establish clinical suitability.
References & editorial record
Source notes checked 2026-10-04. Original PepsRadar summaries. Not reviewed by a medical professional. Topic grouping is editorial navigation, not a treatment recommendation. Video notes specify which excerpts were reviewed; no full transcripts are published.