Not FDA approved and sold as a research chemical. This page is educational information only. It is not medical advice and not a recommendation to use anything.

IndexedBuilt automatically from public databases on 2026-09-30. Not yet hand-reviewed by PLOBT.How this works →

IGF-1 LR3

Not FDA approved

Synthetic IGF-1 analog

Also known as: Long R3 IGF-1

Evidence score

14/ 100

Thin evidence

Very thin human evidence

Regulatory standing. Sold as a research chemical, not approved
Animal / preclinical only. Evidence is largely animal or in-vitro
No registered human trials. Nothing registered on ClinicalTrials.gov
No sources. Nothing cited to verify

Computed with the same four public criteria as every profile. The human-evidence grade on an indexed profile is set automatically and may change when it is hand-reviewed. It is not a safety score, not a purity rating, and not medical advice, and not a claim that this compound treats, cures, or prevents any condition.

What it is

IGF-1 LR3 (Long R3 IGF-1) is a modified form of human insulin-like growth factor 1, with an arginine substitution at position 3 and a 13 amino acid extension at the start of the chain. These changes reduce binding to IGF-binding proteins, which is thought to make it longer acting and more potent than native IGF-1 at the IGF-1 receptor. It is mainly used as a reagent in cell culture and laboratory research.

What the evidence shows

Automatic summaryAnimal / preclinical

There are no registered human trials, and the small published literature is largely cell culture and animal work, so its effects and safety in humans are not established. It is not approved for any use, and a related but different compound, mecasermin (native recombinant IGF-1), is the approved IGF-1 product.

Registered human trials

Live from ClinicalTrials.gov, refreshed daily.

0registered studies

Nonemost advanced phase

0completed (sample)

0recruiting (sample)

Published literature

Live from Europe PMC. This is how much has been published, not how much is proven in humans.

11papers referencing IGF-1 LR3

Extracellular signal-regulated kinase and phosphoinositol-3 kinase mediate IGF-1 induced proliferation of fetal sheep cardiomyocytes.

Am J Physiol Regul Integr Comp Physiol2003

IGF-1 infusion to fetal sheep increases organ growth but not by stimulating nutrient transfer to the fetus.

Am J Physiol Endocrinol Metab2021

Coronary vascular growth matches IGF-1-stimulated cardiac growth in fetal sheep.

FASEB J2020

Reduced glucose-stimulated insulin secretion following a 1-wk IGF-1 infusion in late gestation fetal sheep is due to an intrinsic islet defect.

Am J Physiol Endocrinol Metab2021

Sources

Risks, side effects and study doses are only published on hand-reviewed profiles. Want this one reviewed, or spotted something wrong? Tell us.