Independent · non-commercial · publishes on a quarterly cycle|Current cycle 2026 Q3
Compound Evidence InstituteEvidence synthesis · established 2023Graded assessments of compounds, trials, methods and supply
Document set current to 30 July 2026
Compound monograph · Growth-hormone axis

IGF-1 LR3 — compound monograph

Recombinant insulin-like growth factor 1 analogue. Unapproved, research supply. The Institute assesses 2 outcomes for this compound and grades the strongest at very low certainty.

Document identifier
CEI-MN-029
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

§1Identification and status

§1.1Nomenclature

Preferred name
IGF-1 LR3
Compound class
Recombinant insulin-like growth factor 1 analogue
Assessment series
Growth-hormone axis
Synonyms and codes
Long R3 IGF-1 · LR3 IGF-1 · IGF-1 Long Arg3
Route as evaluated
Subcutaneous in research contexts

§1.2Chemistry

Chemical identifiers are reproduced where they are public. Where a structure has not been published the monograph records not disclosed rather than constructing one.[1]

CAS registry number
946870-92-4
Molecular formula
not applicable (recombinant protein)
Average mass
≈9111 Da
Monoisotopic mass
not applicable
ATC classification
not assigned

§1.3Sequence and structural notes

A 83-residue analogue of human IGF-1 with a 13-residue N-terminal extension and arginine substituted for glutamate at position 3

The arginine-3 substitution markedly reduces affinity for IGF-binding proteins, and the N-terminal extension further extends circulating half-life. It is a recombinant protein expressed in bacterial culture, not a synthetic peptide, and it is frequently misrepresented as the latter.

§1.4Assessment status

The Institute assesses IGF-1 LR3 across 2 indications and grades the strongest of them at very low certainty. Supplied as a research chemical; no marketing authorisation for the uses under which it is supplied.

Distribution of certainty ratingsShare of assessed outcomes at each certainty level.2assessed outcomes
HighModerateLowVery low
Figure 1. Distribution of certainty ratings across the 2 outcomes the Institute assesses for IGF-1 LR3. A rating attaches to a specific population, comparator and outcome and does not transfer between them.

Table 1. Assessed outcomes for IGF-1 LR3, ordered by certainty. Each row links to the per-indication evidence extract.

IndicationEffect as recordedCertaintyTrials
Growth hormone deficiency and growth-hormone secretagogue pharmacologyNo randomised human evidence identified for this analogueVery low0
Sarcopenia and lean-mass preservation during weight reductionNo randomised human evidence identified for this analogueVery low0
Effects are reproduced as the contributing trials reported them. Where a confidence interval is held it appears on the per-indication extract rather than in this summary table.

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

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.

Nothing published by the Institute is medical advice, a diagnosis, a prescription, a treatment recommendation or a purchasing recommendation. Compounds supplied for research use are not approved for human or veterinary use in any jurisdiction, and a favourable analytical assessment of a supplier is not a statement that any product is safe or effective. The Institute publishes certainty ratings and never recommendations. No telephone number, messaging handle or ordering channel appears anywhere on this site.