Tesamorelin 10 mg

What is Tesamorelin?

Tesamorelin is a synthetic analogue of human growth-hormone-releasing hormone (GHRH, also known as somatoliberin or GRF). The peptide comprises all 44 amino acids of the natural sequence and additionally carries a (3E)-hex-3-enoyl group, also called trans-3-hexenoyl, on the N-terminal tyrosine. Pharmacologically it is classed as an agonist at the GHRH receptor (GHRHR), which is located on the somatotroph cells of the anterior pituitary. In databases it also appears under the research code TH9507 and under systematic names such as N-[(3E)-hex-3-enoyl]-hGHRH(1-44)-NH2; tesamorelin acetate denotes the acetate salt form.

Structure and key data

• Sequence (44 amino acids): (trans-3-Hexenoyl)-YADAIFTNSYRKVLGQLSARKLLQDIMSRQQGESNQERGARARL-NH2
• C-terminus: leucinamide, as in the natural hormone
• Molecular formula: C221H366N72O67S
• Molar mass: 5135.9 g/mol (free peptide)
• CAS number: 218949-48-5
• PubChem CID: 16137828

The only sulfur atom in the formula comes from the methionine at position 27. Compared with the unmodified sequence hGHRH(1-44)-NH2, the hexenoyl group makes the molecule around 96 Da heavier by calculation.

Classification: Tesamorelin and related peptides

A comparison with CJC-1295 (No DAC) shows the difference between a full-length and a truncated GHRH analogue: Tesamorelin retains all 44 residues and modifies only the N-terminus, whereas CJC-1295 (No DAC) is shortened to the first 29 amino acids and substitutes four positions within them. The first 29 residues of Tesamorelin, by contrast, are identical to the natural sequence. Ipamorelin is in the same shop category but belongs to the GHRP peptides and is assigned to the ghrelin receptor, not the GHRH receptor. An overview of both families is given in the GHRH & GHRP Peptides category.

Research context

Tesamorelin is studied as a GHRH receptor agonist in research on the somatotropic axis, i.e. the regulatory loop formed by growth hormone (GH) and IGF-1. Typical model systems are preclinical models of GH release from the pituitary. Chemically, the molecule is also an example of how a natural peptide sequence can be modified by a small acyl group at the start of the chain without changing the amino-acid sequence itself.

Analytics at GPeptides

For Tesamorelin, the regular external testing by HPLC and mass spectrometry has two focal points. With 44 residues it is the longest peptide in the GH category, which makes the separation of deletion sequences lacking individual amino acids all the more important. A particular checkpoint is the methionine at position 27: if it oxidises to the sulfoxide, a by-product 16 Da heavier is formed, which can appear as a separate peak in the chromatogram and as a shifted signal in the mass spectrum. For identity testing, the mass is back-calculated from multiply charged ions under electrospray ionisation and compared with the calculated average of around 5136 Da. Which by-products are typical of peptides is described in the guide Purity of research peptides. Available certificates of analysis (COA) can be found in the lab area; those not yet published are marked as “pending”.