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Compound Evidence InstituteEvidence synthesis · established 2023Graded assessments of compounds, trials, methods and supply
Document set current to 30 July 2026
Compound monograph · §2

IGF-1 LR3 — pharmacology

Molecular targets, mechanism of action, pharmacokinetics and interactions as characterised in humans.

Document identifier
CEI-MN-029/2
Series
Compound monograph
Version
3.0
Published
18 Feb 2024
Last reviewed
18 Jun 2024
Next review
18 Jun 2026
Identifier
10.71829/cei.mono.29
Certainty
Very low
Cycle
2024 Q1

§2Pharmacology

§2.1Molecular targets

Table 2. Molecular targets recorded for IGF-1 LR3, with the character of the interaction and the potency where the Institute holds it.

TargetInteractionNote
IGF-1 receptor (IGF1R)AgonistRetains high affinity
Insulin receptorWeak agonistCross-reactivity is the basis of the hypoglycaemia risk
IGF-binding proteins 1–6Markedly reduced bindingThe design feature that extends half-life and simultaneously removes a physiological buffering mechanism

§2.2Mechanism of action

IGF-1 receptor agonism with greatly reduced binding-protein sequestration. The consequence is a sustained, unbuffered IGF-1 receptor signal. Because the IGF-binding proteins normally constrain free IGF-1 to a small fraction of total, removing that constraint changes the pharmacology qualitatively rather than merely quantitatively, and the Institute regards the safety implications as under-appreciated.[1,2]

§2.3Pharmacokinetics

Terminal half-life
reported as substantially longer than native IGF-1, whose free half-life is approximately 10 minutes
Time to maximum concentration
not published
Volume of distribution
not published
Plasma protein binding
markedly reduced
Clearance
not published
Bioavailability
not published

Not characterised in humans for this analogue.

Reconstructed plasma concentration–time profilePlasma concentration plotted against time after dosing, reconstructed from published pharmacokinetic parameters.0.00.20.40.60.801122Time after first dose (hours)Relative concentrationt max ≈ 0 ht½ ≈ 1 h
Modelled profileSimulated observationsDose administration
Figure 2. Illustrative. Plasma concentration–time profile reconstructed by the Institute from the published half-life and time-to-maximum-concentration parameters using a one-compartment model with first-order absorption. The curve is not digitised from a published figure and its vertical scale is relative. It is published to convey the shape of the profile and the approach to steady state, not to supply a concentration at any time point.

§2.4Interactions

  • Insulin and secretagogues — additive hypoglycaemia risk

References cited on this page

References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.

  1. International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use. ICH Q6B Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products. ICH Harmonised Tripartite Guideline 1999;Step 4 version. identifier not held by the Institute
  2. United States Pharmacopeial Convention. General Chapter ⟨85⟩ Bacterial Endotoxins Test. United States Pharmacopeia — National Formulary (USP–NF) 2024;USP 2024 Issue 1. identifier not held by the Institute

Identifiers are reproduced only where the Institute holds them. Where a digital object identifier or PubMed identifier is not shown, the Institute has recorded the journal and year and has not constructed an identifier.

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