IGF-1 LR3 — RQS Scoring Log

IGF-1 LR3

Growth Hormone· Animal / In Vitro· Scored June 2026· View compound profile →

34 /100

Weak Evidence

7 dimensions · 100 points total · Methodology by PeptideClear

What this score covers

This score is for IGF-1 LR3 specifically — the long-acting research analog — not for native IGF-1. Native IGF-1 (mecasermin) is an FDA-approved drug with a strong clinical literature. IGF-1 LR3 is a distinct engineered molecule used almost entirely as a cell-culture reagent and in the gray-market anabolic scene, with essentially no human clinical trials of its own. The two should not be conflated.

Dimension Breakdown

Dimension	Scoring Notes	Score
Study Design	Direct evidence for the LR3 analog is in vitro cell-proliferation work and a handful of animal anabolic-growth studies (e.g. Tomas, Conlon and colleagues in rodents and sheep). No human trials of the analog itself. The native-IGF-1 RCT base does not transfer to this modified molecule.	10 / 25
Sample Size	Small animal and in-vitro studies only; no human sample for the analog.	4 / 20
Replication	IGF-1 receptor agonism is well replicated mechanistically, but LR3-specific anabolic outcomes have limited independent reproduction.	6 / 20
Journal Impact Factor	Published across endocrinology, animal-science, and biochemistry journals — mixed mid-tier venues.	6 / 15
Funding Independence	The LR3 design originated in academic / public-research groups (the IGF biology work of Ballard, Francis and colleagues). Reasonably independent in origin, though now overwhelmingly a commercialized research reagent.	5 / 10
Population Diversity	No human populations studied for the analog; rodent and cell-line models only.	0 / 5
Researcher h-Index	The broader IGF-1 field carries strong researchers, but the LR3-specific literature is modest in citation weight.	3 / 5

Dimension

Scoring Notes

Score

Study Design

Direct evidence for the LR3 analog is in vitro cell-proliferation work and a handful of animal anabolic-growth studies (e.g. Tomas, Conlon and colleagues in rodents and sheep). No human trials of the analog itself. The native-IGF-1 RCT base does not transfer to this modified molecule.

10 / 25

Sample Size

Small animal and in-vitro studies only; no human sample for the analog.

4 / 20

Replication

IGF-1 receptor agonism is well replicated mechanistically, but LR3-specific anabolic outcomes have limited independent reproduction.

6 / 20

Journal Impact Factor

Published across endocrinology, animal-science, and biochemistry journals — mixed mid-tier venues.

6 / 15

Funding Independence

The LR3 design originated in academic / public-research groups (the IGF biology work of Ballard, Francis and colleagues). Reasonably independent in origin, though now overwhelmingly a commercialized research reagent.

5 / 10

Population Diversity

No human populations studied for the analog; rodent and cell-line models only.

0 / 5

Researcher h-Index

The broader IGF-1 field carries strong researchers, but the LR3-specific literature is modest in citation weight.

3 / 5

Sources: PubMed — analog-specific anabolic studies by Tomas, Conlon, Owens and colleagues; native IGF-1 / mecasermin clinical literature for context. Key journals: Journal of Endocrinology, Journal of Animal Science. Funding: academic / public-research origin, now a commercialized research reagent. (PMIDs to be confirmed before publish — see note.)

Note: IGF-1 LR3 is an 83-amino-acid analog of native IGF-1 carrying a 13-residue N-terminal extension and a position-3 substitution that cut its binding-protein affinity roughly 1,000-fold, extending its half-life from minutes to roughly a day. That engineering is exactly why it is useful in the lab and why its evidence base is a research one. It is sold strictly “for research use only” and is not approved for human use. The Weak score reflects the analog's own thin direct evidence, not the well-studied native hormone it is derived from.

Scored by the PeptideClear editorial team using publicly available literature. Sources: PubMed (study design, sample size, replication) · ScimagoJR (journal impact factor) · Google Scholar (researcher h-Index) · Primary papers (funding disclosure). Scores are reviewed as new research is published.