What Is Tesamorelin?
Tesamorelin is a stabilized synthetic analog of growth-hormone-releasing hormone, GHRH(1-44). Unlike most research peptides, a tesamorelin drug product is FDA-approved for a specific indication — see the regulatory note below.
The short answer
Tesamorelin is a GHRH(1-44) analog carrying a modification that improves its stability relative to native GHRH. It acts on the GHRH receptor and, in the research literature, is the most clinically characterized peptide in this cluster because a tesamorelin drug product has been studied and approved in a defined medical indication.
Composition and specifications
| Compound | Tesamorelin (GHRH 1-44 analog) |
|---|---|
| Class | Stabilized GHRH(1-44) analog |
| Also known as | GRF(1-44) analog |
| Sequence / length | 44 amino acids (GHRH 1-44 analog) |
| CAS number | 218949-48-5 |
| Molecular weight | 5135.9 g/mol |
| Purity (typical) | ≥99.0% |
| Appearance | White lyophilized powder; water-soluble |
Values above reflect the compound's published specification. As with any research material, the definitive confirmation of identity and purity for a given lot is the mass-spectrometry and HPLC data on its Certificate of Analysis.
How it is described mechanistically
Tesamorelin binds the GHRH receptor, where it is associated with stimulation of endogenous growth-hormone secretion. Its N-terminal modification is intended to resist enzymatic degradation, giving it a longer effective window than native GHRH in research models.
What has research examined?
Tesamorelin has a comparatively deep evidence base for a peptide in this category. Areas examined include:
- GHRH-receptor signaling and growth-hormone/IGF-1 research
- Visceral adipose tissue research (its approved-drug indication studied HIV-associated lipodystrophy)
- Metabolic and body-composition research models
- Comparisons with other GHRH-based analogs
The existence of an approved tesamorelin drug product does not make research-grade material a medicine; the two are different products with different intended uses.
How is it characterized and tested?
Two questions matter most about any peptide sample in a research context: is it the right molecule, and how pure is it. Those are answered by analytical testing — commonly mass spectrometry for identity and HPLC for purity — with both reported on a batch-specific Certificate of Analysis (COA). An independent, published COA lets a researcher confirm identity and purity before beginning work. See peptide handling and storage for how samples are kept stable once received.
Primary literature: browse peer-reviewed studies on Tesamorelin at PubMed.
Common questions
Is tesamorelin FDA-approved?
A tesamorelin drug product (marketed as Egrifta) is FDA-approved for a specific medical indication. The research-grade material offered here is not that approved product and is supplied for laboratory research use only.
What is the difference between tesamorelin and CJC-1295 or sermorelin?
All three are GHRH-based. Sermorelin is GHRH(1-29); tesamorelin is a stabilized GHRH(1-44) analog; CJC-1295 is a modified GHRH(1-29) analog. They differ in length, stability, and how they are studied.
How is research-grade tesamorelin stored?
Keep the lyophilized peptide cold, dry, and protected from light, with different handling once reconstituted.