Tesamorelin

Tesamorelin (TH9507) is a synthetic analogue of the full-length native growth hormone-releasing factor, GRF(1-44)-NH2, a 44-residue peptide. It is minimally modified by attachment of a trans-3-hexenoyl group to the N-terminal Tyr1 residue, a change that makes the peptide resistant to inactivation by dipeptidyl aminopeptidase-IV. The molecule has the formula C221H366N72O67S and a molar mass of about 5,136 g/mol, and it is grouped with sermorelin and CJC-1295 among the synthetic analogues of growth hormone-releasing hormone (GHRH).

Tesamorelin in the research literature

Preclinical pharmacology work reported that the hexenoyl modification slowed in vitro degradation of the peptide in rat and dog plasma relative to unmodified GRF(1-44)-NH2 and prolonged its plasma elimination kinetics in vivo. Repeated exposure in pigs, rats and dogs markedly increased circulating growth hormone and insulin-like growth factor-1 (IGF-1). Subchronic toxicology studies in rats and dogs lasting up to four months characterized responses attributed to sustained supraphysiological growth hormone and IGF-1 levels, including reversible liver, kidney and hematological findings in dogs, and the apparent elimination half-life in dogs ranged from 21 to 45 minutes.

On the analytical side, nano-liquid chromatography methods coupled with quadrupole/orbitrap mass spectrometry have been validated for detecting tesamorelin alongside other GHRH analogues in urine at sub-nanogram-per-millilitre levels.