Also known as Long R3 IGF-1 · LR3 IGF-1
A long-acting modified IGF-1 analog with reduced IGFBP binding and prolonged systemic activity.
IGF-1 LR3 (Long R3 IGF-1) is an 83-amino-acid analog of IGF-1 with an arginine substitution at position 3 and a 13-residue N-terminal extension. These changes reduce binding to IGF-binding proteins, extending its half-life and potency versus native IGF-1.
IGF-1 LR3 ("Long R3 IGF-1") is a modified version of insulin-like growth factor 1, engineered for a much longer duration of action. Two changes define it: arginine replaces glutamic acid at position 3, and a 13-amino-acid extension is added to the N-terminus.
Together these reduce the analog’s affinity for IGF-binding proteins — the carriers that normally sequester circulating IGF-1 — so more remains free and active, extending half-life and increasing potency roughly two- to three-fold over native IGF-1 (~9.1 kDa). It is a research compound, widely used in cell culture, and is not FDA-approved; it is also prohibited in sport.
IGF-1 receptor agonism with reduced IGFBP binding → prolonged systemic anabolic signaling.
Behind every vial of IGF-1 LR3 is the same exacting pipeline every research peptide runs — but the chemistry plays out differently for this molecule. Here is how IGF-1 LR3, specifically, is brought into being.
IGF-1 LR3 begins not as a powder but as a specification. Before a single bond is made, the target sequence, salt form, and purity threshold are written down as the contract the finished material must meet.
IGF-1 LR3 is assembled by solid-phase peptide synthesis — the chain grows one protected residue at a time on resin, and what you fail to build cleanly here you pay to remove later.
The crude mixture — IGF-1 LR3 plus its deletions and side products — is then separated on preparative HPLC, and where the cut is taken decides the difference between a genuinely pure peptide and a barely-passable one.
A real batch of IGF-1 LR3 proves itself: identity confirmed by mass spectrometry, purity read directly off an analytical HPLC trace, water and counterion content measured. That batch-specific certificate of analysis is the only honest way to know what is actually in a vial of IGF-1 LR3 — and a short, cold, accountable chain of custody is how that purity survives the trip to your bench.
Producing IGF-1 LR3 to a genuine purity spec means solid-phase synthesis, preparative HPLC purification, and batch quality control — none of it cheap, and none of it something you can verify by eye.
Don't judge a vial by its cake. A fluffy, good-looking lyophilized powder reflects bulking agents and freeze-drying parameters — not purity. Insist on a batch-specific certificate of analysis.
Recent clinical trials and publications mentioning IGF-1 LR3, pulled automatically from ClinicalTrials.gov and PubMed and refreshed daily. Listings are unfiltered search results, not curated endorsements.
IGF-1 LR3 (Long R3 IGF-1) is a modified, long-acting analog of IGF-1 with an arginine-3 substitution and an N-terminal extension that reduce IGF-binding-protein binding and extend its activity.
It lowers the analog’s affinity for IGF-binding proteins, so more remains free and active in circulation — extending half-life and increasing potency versus native IGF-1.
IGF-1 LR3 is systemic and long-acting, studied for hypertrophy; MGF is a local, transient IGF-1 splice variant studied for satellite-cell activation. The two are typically sequenced, not combined.
No. It is a research compound (also common in cell culture), not FDA-approved, and is prohibited in sport. This page is a research and educational reference.
Recombinant 191-amino-acid human growth hormone — a folded protein biologic identical in sequence to pituitary GH, not a synthetic research peptide.
ViewThe downstream effector of growth hormone — a 70-amino-acid recombinant protein, structurally a cousin of proinsulin, that carries out most of GH’s growth signal.
ViewA splice variant of IGF-1 expressed after muscle damage; studied for satellite-cell activation.
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