Cell / animal study· 1995
Long R3 insulin-like growth factor-I (IGF-I) infusion stimulates organ growth but reduces plasma IGF-I, IGF-II and IGF binding protein concentrations in the guinea pig.
The Journal of endocrinology
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PreclinicalNot FDA-approved
IGF-1 LR3
Modified long-acting IGF-1 analog
Also indexed as: Long-R3 IGF-1
What this evidence does not tell us
Animal organ-growth research and analytical identification of a product are not clinical efficacy trials. LR3 is not mecasermin, an approved IGF-1 medication.
Terms on this page
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7 glossary terms used in this profile
Terms on this page
Unfamiliar word? Open this panel for simple explanations, right here.
7 glossary terms used in this profile
Select a word to see its meaning. You can keep more than one definition open.
Definitions explain the words—not whether a molecule works or is safe. Research education only, not medical advice.
Overview
IGF-1 LR3 is a modified insulin-like growth factor analog used in experimental research. It is not interchangeable with native IGF-1 or the approved medication mecasermin.
Mechanism of action
IGF-1 receptor signaling
Activates IGF-1 receptor signaling with altered interactions with IGF-binding proteins compared with native IGF-1. Experimental effects on growth and metabolism are not proof of safe human use.
A biological pathway describes a proposed or observed interaction—not necessarily a demonstrated health outcome.
Decode the terminology in our glossaryScientific evidence
How strong is the evidence?
Early lab & animal research
- Limited evidence
- Early researchCurrent category
- Human research
- Human outcomes
Most support comes from cells or animals. These studies help form questions, but do not prove a treatment works in people.
For this research: Animal organ-growth research and analytical identification of a product are not clinical efficacy trials. LR3 is not mecasermin, an approved IGF-1 medication.
An editorial guide—not a validated score, a percentage, a safety rating or an approval badge. Regulatory status is separate. More research does not mean fewer risks.
Cell studies
Mechanistic laboratory evidence is not separately assessed in this selected-source summary; see references and their study types.
Animal experiments
The cited guinea-pig study measures organ growth and IGF-binding proteins.
Human observational studies
Associations, biomarker studies and anecdotes cannot establish treatment causality; no observational result is used here to infer clinical effectiveness.
Human clinical trials
Reliable, independently replicated human outcome evidence is not established by the selected sources in this edition.
Regulatory evidence
No FDA-approved finished drug for this molecule is identified in this edition. Investigational use, published research or compounding does not establish FDA approval.
Potential research applications
Growth-factor signaling in cell culture and animal models.
These describe scientific questions, not prescribing recommendations. A research grouping does not establish combination safety or clinical effectiveness.
Explore research by health goalSafety considerations
IGF signaling can affect glucose and growth pathways; hypoglycemia and unintended tissue growth are concerns. Human safety for this analog is not established.
This is not an exhaustive safety or contraindication list. An absence of reported harm is not proof of safety. Pregnancy, breastfeeding, cancer history, endocrine disease and concurrent medicines can materially change risk. Unregulated preparations add identity, contamination and sterility risks.
Regulatory status · United States
Not FDA-approved
No FDA-approved finished drug for this molecule is identified in this edition. Investigational use, published research or compounding does not establish FDA approval.
Regulatory status and evidence strength are different. A nomination for compounding, a clinical-trial registration or a “research use only” label is not approval. International rules vary; consult the current regulator and product label.
Selected literature & source transparency
Analytical study· 2010
Detection of His-tagged Long-R³-IGF-I in a black market product.
Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society
Matched bibliographic records confirm a publication’s identity, not the validity of every claim. Selected sources are not a systematic literature review.
Continue your own source search
These open search results, not additional verified citations. Trial registration is not evidence that a treatment works.
Three questions worth bringing to your clinician
- Which human outcomes—not just biomarkers—support this claim?
- What established options address my actual health concern?
- What do my medical history and current medicines change about the risks?
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