IGF-1 LR3 vs Tesamorelin
Direct IGF-1 receptor agonism versus upstream GHRH stimulation — acting at opposite ends of the same axis.
Growth Hormone
IGF-1 LR3
83-amino-acid IGF-1 analog engineered for markedly reduced binding to IGF binding proteins.
Growth Hormone
Tesamorelin
Stabilized 44-amino-acid GHRH analog — the longest GHRH sequence in common research use.
Side by side
| Dimension | IGF-1 LR3 | Tesamorelin |
|---|---|---|
| Molecular weight | 9117.6 g/mol | 5135.86 g/mol |
| Size class | protein-scale | long peptide |
| CAS number | 946870-92-4 | 218949-48-5 |
| Research area | growth hormone | growth hormone |
| Sequence | Not published as a linear sequence | Not published as a linear sequence |
| Available sizes | 1mg | 10mg, 15mg |
| Entry price | $69 | $64 |
| Cost per mg Cost per milligram differs by more than 3×. Compare against the concentrations your protocol actually requires, not the headline vial price. | $69.00 | $5.93 |
Mechanism
IGF-1 LR3
IGF-1 LR3 is a recombinant analog of human IGF-1 carrying two modifications: an arginine substitution at position 3, and a 13-amino-acid N-terminal extension. The Arg3 substitution sharply reduces affinity for IGF binding proteins, which normally sequester the great majority of circulating IGF-1. The practical research consequence is a much larger free fraction and correspondingly extended activity — which also means potency comparisons against native IGF-1 are not straightforward.
Tesamorelin
Tesamorelin is a synthetic analog of full-length human GHRH(1-44) with a trans-3-hexenoyl group attached at the N-terminus, conferring resistance to DPP-4 cleavage. It is distinguished from sermorelin and Modified GRF (1-29) by sequence length: those are truncated to the first 29 residues, whereas tesamorelin retains the complete 44-residue sequence. It has an established clinical literature, which is uncommon in this catalog.
Evidence quality
Mechanism is not the same as evidence. Where we have assessed the literature, the verdict is stated plainly.
IGF-1 LR3
Evidence base: very thin, sixteen indexed results, dominated by fetal sheep models. The most recent primary result in that model is negative, and a 2025 mouse study shows biomarker change without functional benefit.
Full research reference →Tesamorelin
Evidence base: strong for the approved indication, supported by pooled phase 3 data with safety extension. Evidence outside that population and endpoint is limited, and the recent neurocognitive work is single-study.
Full research reference →Research applications
IGF-1 LR3
- IGF-1 receptor binding and autophosphorylation assays
- IGFBP interaction and displacement studies
- Cell proliferation and differentiation in culture
- Akt/mTOR pathway signaling research
Tesamorelin
- GHRH receptor binding and activation studies
- Comparative studies against truncated GHRH analogs
- Visceral adipose tissue metabolism research
- IGF-1 axis response profiling
Common questions
What is the difference between IGF-1 LR3 and Tesamorelin?
IGF-1 LR3 is 83-amino-acid IGF-1 analog engineered for markedly reduced binding to IGF binding proteins. Tesamorelin is stabilized 44-amino-acid GHRH analog — the longest GHRH sequence in common research use. They differ in molecular weight (9117.6 vs 5135.86 g/mol) and in the pathways they are studied against.
Which is more cost-effective per milligram, IGF-1 LR3 or Tesamorelin?
Tesamorelin is lower at approximately $5.93 per milligram at its best tier, against $69.00 for the other. Cost per milligram is only meaningful relative to the concentrations a given protocol requires, since these compounds are not used at comparable masses.
Can IGF-1 LR3 and Tesamorelin be studied together?
Combination designs appear in the published literature for a number of these compounds. Whether it is appropriate for a given protocol depends entirely on the model and endpoint. We supply research compounds and do not provide protocol guidance — consult the primary literature for your specific model.
How should IGF-1 LR3 and Tesamorelin be stored?
Store lyophilized at -20°C protected from light. This is a larger protein than most of the catalog and is more sensitive to freeze-thaw; aliquot on first reconstitution. For Tesamorelin: Store lyophilized at -20°C protected from light. Reconstituted at 2-8°C for up to 30 days.
Which has the stronger evidence base?
IGF-1 LR3 — Evidence base: very thin, sixteen indexed results, dominated by fetal sheep models. The most recent primary result in that model is negative, and a 2025 mouse study shows biomarker change without functional benefit. Tesamorelin — Evidence base: strong for the approved indication, supported by pooled phase 3 data with safety extension. Evidence outside that population and endpoint is limited, and the recent neurocognitive work is single-study.
All products sold on this website are intended for research and identification purposes only. These products are not intended for human dosing, injection, or ingestion.
Comparison generated from Lyra Vital catalog data. Every specification is reconciled against the certificate of analysis for the shipped batch.